Light emitting element and polycyclic compound for the same

ABSTRACT

A light emitting element includes a first electrode, a second electrode disposed on the first electrode, and at least one functional layer which is disposed between the first electrode and the second electrode, and includes a polycyclic compound represented by Formula 1 below, thereby exhibiting high efficiency and low driving voltage characteristics.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2021-0176439, filed on Dec. 10, 2021, the entirecontent of which is hereby incorporated by reference.

BACKGROUND 1. Field

The present disclosure herein relates to a light emitting element and apolycyclic compound utilized therein, and for example, to a lightemitting element including a polycyclic compound utilized as aluminescent material.

2. Description of the Related Art

Recently, the development of an organic electroluminescence displaydevice as an image display device is being actively conducted. Theorganic electroluminescence display device includes a so-calledself-luminescent light emitting element in which holes and electronsinjected from a first electrode and a second electrode recombine in anemission layer, and thus a luminescent material in the emission layeremits light to implement display (e.g., to display an image).

In the application of a light emitting element to a display device,there is a desire (e.g., a demand) for a light emitting element having alow driving voltage, a high luminous efficiency, and a long service life(e.g., long lifespan), and development on materials for a light emittingelement capable of stably attaining such characteristics is beingcontinuously pursued (e.g., required).

SUMMARY

An aspect according to embodiments of the present disclosure is directedtoward a light emitting element with improved driving voltagecharacteristic and luminous efficiency.

An aspect according to embodiments of the present disclosure is directedtoward a polycyclic compound capable of improving driving voltagecharacteristic and luminous efficiency of a light emitting element.

According to an embodiment of the present disclosure, a light emittingelement includes a first electrode, a second electrode on the firstelectrode, and at least one functional layer between the first electrodeand the second electrode, wherein the at least one functional layerincludes a polycyclic compound represented by Formula 1:

In Formula 1 above, R₁ and R₂ may each independently be a hydrogen atom,a deuterium atom, a cyano group, a substituted or unsubstituted silylgroup, a substituted or unsubstituted alkyl group having 1 to 20 carbonatoms, a substituted or unsubstituted cycloalkyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms; R₃ and R₄ may each independently be ahydrogen atom, a deuterium atom, or a group represented by Formula 2 orFormula 3; a and b may each independently be an integer of 0 to 5, c maybe an integer of 0 to 3, and d may be an integer of 0 to 4.

In Formula 2 above, g may be 0 or 1, when g is 0, the two phenyl groupsof Formula 2 are only connected through the N atom, and when g is 1, Xis a direct linkage.

In Formula 2 and Formula 3 above, R₅ to R₇ may each independently be ahydrogen atom, a deuterium atom, a cyano group, a substituted orunsubstituted silyl group, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylgroup having 3 to 20 ring-forming carbon atoms, a substituted orunsubstituted heterocycloalkyl group having 3 to 20 ring-forming carbonatoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms, and/or bonded to an adjacent group toform a ring, e and f may each independently be an integer of 0 to 4, hmay be an integer of 0 to 5, and

represents a linking position.

In an embodiment, the at least one functional layer may include anemission layer, a hole transport region between the first electrode andthe emission layer, and an electron transport region between theemission layer and the second electrode, and the emission layer mayinclude the polycyclic compound.

In an embodiment, the emission layer may be to emit delayed fluorescenceor phosphorescence.

In an embodiment, the emission layer may include a host and a dopant,and the host may include the polycyclic compound.

In an embodiment, the emission layer may be to emit light having acenter wavelength of about 430 nm to about 480 nm.

In an embodiment, in the polycyclic compound represented by Formula 1above, R₁ and R₂ may each independently be a hydrogen atom, a deuteriumatom, or a substituted or unsubstituted phenyl group.

In an embodiment, in the polycyclic compound represented by Formula 1above, at least one selected from R₃ or R₄ may be represented by Formula2 or Formula 3 above.

In an embodiment, Formula 2 above may be represented by Formula 2-1 orFormula 2-2:

In Formula 2-1 and Formula 2-2 above, R_(5i) and R₆ may eachindependently be a hydrogen atom, a deuterium atom, a substituted orunsubstituted silyl group, a substituted or unsubstituted alkyl grouphaving 1 to 10 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 20 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 20 ring-forming carbon atoms,and e and f may each independently be an integer of 1 to 4.

In an embodiment, the polycyclic compound represented by Formula 1 abovemay be represented by Formula 1-1 or Formula 1-2:

In Formula 1-1 and Formula 1-2 above, Ru may be a hydrogen atom, adeuterium atom, a substituted or unsubstituted alkyl group having 1 to10 carbon atoms, or a substituted or unsubstituted aryl group having 6to 20 ring-forming carbon atoms, and R₅ to R₇, a, e, f, and h may be thesame as respectively defined in Formula 1 to Formula 3 above.

In an embodiment, the polycyclic compound represented by Formula 1-1above may be represented by Formula 1-1-1 or Formula 1-1-2:

In Formula 1-1-1 and Formula 1-1-2 above, R_(1i), R₅, R₆, a, e, and fmay be the same as respectively defined in Formula 1-1 and Formula 2above.

In an embodiment, the polycyclic compound represented by Formula 1-2above may be represented by Formula 1-2-1 or 1-2-2:

In Formula 1-2-1 and Formula 1-2-2 above, R_(1i), R₇, a, and h may bethe same as respectively defined in Formula 1-2 and Formula 3 above.

In an embodiment, R₅ to R₇ above may each independently be a hydrogenatom, a deuterium atom, or a group represented by any one selected fromamong R-1 to R-5:

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this specification. The drawings illustrate exampleembodiments of the present disclosure and, together with thedescription, serve to explain principles of the present disclosure. Inthe drawings:

FIG. 1 is a plan view illustrating a display device according to anembodiment of the present disclosure;

FIG. 2 is a cross-sectional view illustrating a part taken along theline I-I′ of FIG. 1 ;

FIG. 3 is a cross-sectional view schematically illustrating a lightemitting element according to an embodiment of the present disclosure;

FIG. 4 is a cross-sectional view schematically illustrating a lightemitting element according to an embodiment of the present disclosure;

FIG. 5 is a cross-sectional view schematically illustrating a lightemitting element according to an embodiment of the present disclosure;

FIG. 6 is a cross-sectional view schematically illustrating a lightemitting element according to an embodiment of the present disclosure;

FIG. 7 is a cross-sectional view illustrating a display device accordingto an embodiment of the present disclosure;

FIG. 8 is a cross-sectional view illustrating a display device accordingto an embodiment of the present disclosure;

FIG. 9 is a cross-sectional view illustrating a display device accordingto an embodiment of the present disclosure; and

FIG. 10 is a cross-sectional view illustrating a display deviceaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure may be modified in many alternate forms, and thusspecific embodiments will be shown in the drawings and described in thistext in more detail. It should be understood, however, that it is notintended to limit the present disclosure to the particular formsdisclosed, but rather, is intended to cover all modifications,equivalents, and alternatives falling within the spirit and scope of thepresent disclosure.

In the present specification, when a component (or a region, a layer, aportion, etc.) is referred to as being “on,” “connected to,” or “coupledto” another component, it refers to that the component may be directlydisposed on/connected to/coupled to the other component, or that a thirdcomponent may be disposed therebetween.

Like reference numerals refer to like components throughout. Also, inthe drawings, the thicknesses, ratios, and dimensions of the componentsmay be exaggerated for effective description of technical contents. Theterm “and/or” includes all combinations of one or more of whichassociated configurations may define.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe one or more suitable components, thesecomponents should not be limited by these terms. These terms are onlyused to distinguish one component from another. For example, a firstcomponent could be termed a second component, and, similarly, a secondcomponent could be termed a first component, without departing from thescope of the present disclosure. As used herein, the singular forms,“a,” “an,” and “the” are intended to include the plural forms as well,unless the context clearly indicates otherwise.

In addition, terms such as “below,” “under,” “on,” and “above” may beused to describe the relationship between components illustrated in thedrawings. The terms are used as a relative concept and are describedwith reference to the direction indicated in the drawings.

It should be understood that the terms “comprise,” or “have” areintended to specify the presence of stated features, integers, steps,operations, components, parts, or combinations thereof in thedisclosure, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, components, parts, orcombinations thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which the present disclosure belongs. Inaddition, it will be understood that terms, such as those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

In the present application, when a part such as a layer, a film, aregion, or a plate is referred to as being “on” or “above” another part,it can be directly on the other part, or an intervening part may also bepresent. On the contrary, when a part such as a layer, a film, a region,or a plate is referred to as being “under” or “below” another part, itcan be directly under the other part, or an intervening part may also bepresent. In addition, it will be understood that when a part is referredto as being “on” another part, it can be disposed on the other part, ordisposed under the other part as well.

In the specification, the term “substituted or unsubstituted” may referto a functional group that is substituted or unsubstituted with at leastone substituent selected from the group consisting of a deuterium atom,a halogen atom, a cyano group, a nitro group, an amine group, a silylgroup, an oxy group, a thio group, a sulfinyl group, a sulfonyl group, acarbonyl group, a boron group, a phosphine oxide group, a phosphinesulfide group, an alkyl group, an alkenyl group, an alkynyl group, analkoxy group, a hydrocarbon ring group, an aryl group, and aheterocyclic group. In addition, each of the substituents describedabove may be substituted or unsubstituted. For example, a biphenyl groupmay be interpreted as an aryl group or a phenyl group substituted with aphenyl group.

In the specification, the phrase “bonded to an adjacent group to form aring” may indicate that a group is bonded to an adjacent group to form asubstituted or unsubstituted hydrocarbon ring, or a substituted orunsubstituted heterocycle. The hydrocarbon ring includes an aliphatichydrocarbon ring and an aromatic hydrocarbon ring. The heterocycleincludes an aliphatic heterocycle and an aromatic heterocycle. Thehydrocarbon ring and the heterocycle may be monocyclic or polycyclic. Inaddition, the rings formed by adjacent groups being bonded to each othermay be connected to another ring to form a spiro structure.

In the specification, the term “adjacent group” may refer to asubstituent substituted for an atom which is directly linked to an atomsubstituted with a corresponding substituent, another substituentsubstituted for an atom which is substituted with a correspondingsubstituent, or a substituent sterically positioned at the nearestposition to a corresponding substituent. For example, two methyl groupsin 1,2-dimethylbenzene may be interpreted as “adjacent groups” to eachother and two ethyl groups in 1,1-diethylcyclopentane may be interpretedas “adjacent groups” to each other. In addition, two methyl groups in4,5-dimethylphenanthrene may be interpreted as “adjacent groups” to eachother.

In the specification, examples of the halogen atom may include afluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

In the specification, the alkyl group may be a linear, branched orcyclic alkyl group. The number of carbon atoms in the alkyl group may be1 to 60, 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of thealkyl group may include a methyl group, an ethyl group, an n-propylgroup, an isopropyl group, an n-butyl group, an s-butyl group, a t-butylgroup, an i-butyl group, a 2-ethylbutyl group, a 3,3-dimethylbutylgroup, an n-pentyl group, an i-pentyl group, a neopentyl group, at-pentyl group, a cyclopentyl group, a 1-methylpentyl group, a3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group,an n-hexyl group, a 1-methylhexyl group, a 2-ethylhexyl group, a2-butylhexyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a4-t-butylcyclohexyl group, an n-heptyl group, a 1-methylheptyl group, a2,2-dimethylheptyl group, a 2-ethylheptyl group, a 2-butylheptyl group,an n-octyl group, a t-octyl group, a 2-ethyloctyl group, a 2-butyloctylgroup, a 2-hexyloctyl group, a 3,7-dimethyloctyl group, a cyclooctylgroup, an n-nonyl group, an n-decyl group, an adamantyl group, a2-ethyldecyl group, a 2-butyldecyl group, a 2-hexyldecyl group, a2-octyldecyl group, an n-undecyl group, an n-dodecyl group, a2-ethyldodecyl group, a 2-butyldodecyl group, a 2-hexyldocecyl group, a2-octyldodecyl group, an n-tridecyl group, an n-tetradecyl group, ann-pentadecyl group, an n-hexadecyl group, a 2-ethylhexadecyl group, a2-butylhexadecyl group, a 2-hexylhexadecyl group, a 2-octylhexadecylgroup, an n-heptadecyl group, an n-octadecyl group, an n-nonadecylgroup, an n-eicosyl group, a 2-ethyleicosyl group, a 2-butyleicosylgroup, a 2-hexyleicosyl group, a 2-octyleicosyl group, an n-henicosylgroup, an n-docosyl group, an n-tricosyl group, an n-tetracosyl group,an n-pentacosyl group, an n-hexacosyl group, an n-heptacosyl group, ann-octacosyl group, an n-nonacosyl group, an n-triacontyl group, etc.,but the embodiment of the present disclosure is not limited thereto.

The term “hydrocarbon ring group” as used herein refers to anyfunctional group or substituent derived from an aliphatic hydrocarbonring or a ring in which an aliphatic hydrocarbon ring group and anaromatic hydrocarbon ring are fused. The number of ring-forming carbonatoms in the hydrocarbon ring group may be 5 to 60, 5 to 30, or 5 to 30.

In the specification, the term “aryl group” refers to any functionalgroup or substituent derived from an aromatic hydrocarbon ring. The arylgroup may be a monocyclic aryl group or a polycyclic aryl group. Thenumber of ring-forming carbon atoms in the aryl group may be 6 to 60, 6to 30, 6 to 20, or 6 to 15. Examples of the aryl group may include aphenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group,a phenanthryl group, a biphenyl group, a terphenyl group, a quaterphenylgroup, a quinquephenyl group, a sexiphenyl group, a triphenylenyl group,a pyrenyl group, a benzofluoranthenyl group, a chrysenyl group, etc.,but the embodiment of the present disclosure is not limited thereto.

In the specification, the term “heterocyclic group” refers to anyfunctional group or substituent derived from a ring containing at leastone of B, 0, N, P, Se, Si, or S as a heteroatom. The heterocyclic groupincludes an aliphatic heterocyclic group and an aromatic heterocyclicgroup. The aromatic heterocyclic group may be a heteroaryl group. Thealiphatic heterocycle and the aromatic heterocycle may be monocyclic orpolycyclic.

When the heterocyclic group includes two or more heteroatoms, the two ormore heteroatoms may be the same as or different from each other. Theheterocyclic group may be a monocyclic heterocyclic group or apolycyclic heterocyclic group and may include a heteroaryl group. Thenumber of ring-forming carbon atoms in the heterocyclic group may be 2to 60, 2 to 30, 2 to 20, or 2 to 10.

In the specification, the aliphatic heterocyclic group may contain atleast one of B, 0, N, P, Se, Si, or S as a heteroatom. The number ofring-forming carbon atoms of the aliphatic heterocyclic group may be 2to 30, 2 to 20, or 2 to 10. Examples of the aliphatic heterocyclic groupmay include an oxirane group, a thiirane group, a pyrrolidine group, apiperidine group, a tetrahydrofuran group, a tetrahydrothiophene group,a thiane group, a tetrahydropyran group, a 1,4-dioxane group etc., butthe embodiment of the present disclosure is not limited thereto.

In the specification, the heteroaryl group may contain at least one ofB, 0, N, P, Se, Si, or S as a heteroatom. When the heteroaryl groupcontains two or more heteroatoms, the two or more heteroatoms may be thesame as or different from each other. The heteroaryl group may be amonocyclic heteroaryl group or a polycyclic heteroaryl group. The numberof ring-forming carbon atoms in the heteroaryl group may be 2 to 30, 2to 20, or 2 to 10. Examples of the heteroaryl group may include athiophene group, a furan group, a pyrrole group, an imidazole group, apyridine group, a bipyridine group, a pyrimidine group, a triazinegroup, a triazole group, an acridyl group, a pyridazine group, apyrazinyl group, a quinoline group, a quinazoline group, a quinoxalinegroup, a phenoxazine group, a phthalazine group, a pyrido pyrimidinegroup, a pyrido pyrazine group, a pyrazino pyrazine group, anisoquinoline group, an indole group, a carbazole group, anN-arylcarbazole group, an N-heteroarylcarbazole group, anN-alkylcarbazole group, a benzoxazole group, a benzimidazole group, abenzothiazole group, a benzocarbazole group, a benzothiophene group, adibenzothiophene group, a thienothiophene group, a benzofuran group, aphenanthroline group, a thiazole group, an isoxazole group, an oxazolegroup, an oxadiazole group, a thiadiazole group, a phenothiazine group,a dibenzosilole group, a dibenzofuran group, etc., but the embodiment ofthe present disclosure is not limited thereto.

In the specification, the above description of the aryl group may beapplied to an arylene group except that the arylene group is a divalentgroup. The above description of the heteroaryl group may be applied to aheteroarylene group except that the heteroarylene group is a divalentgroup.

In the specification, the fluorenyl group may be substituted, and twosubstituents may be bonded to each other to form a spiro structure.Examples of cases where the fluorenyl group is substituted are asfollows. However, the embodiment of the present disclosure is notlimited thereto.

In the specification, a silyl group includes an alkyl silyl group and anaryl silyl group. Examples of the silyl group may include atrimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilylgroup, an ethyldimethylsilyl group, a propyldimethylsilyl group, atriphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, etc.,but the embodiment of the present disclosure is not limited thereto.

In the specification, a thio group may include an alkylthio group and anarylthio group. The thio group may refer to that a sulfur atom is bondedto the alkyl group or the aryl group as defined above. Examples of thethio group may include a methylthio group, an ethylthio group, apropylthio group, a pentylthio group, a hexylthio group, an octylthiogroup, a dodecylthio group, a cyclopentylthio group, a cyclohexylthiogroup, a phenylthio group, and/or a naphthylthio group, but theembodiment of the present disclosure is not limited thereto.

In the specification, an oxy group may refer to that an oxygen atom isbonded to the alkyl group or the aryl group as defined above. The oxygroup may include an alkoxy group and an aryl oxy group. The alkoxygroup may be a linear chain, a branched chain or a ring chain. Thenumber of carbon atoms in the alkoxy group is not specifically limited,but may be, for example, 1 to 60, 1 to 20 or 1 to 10. The number ofring-forming carbon atoms in the aryloxy group is not specificallylimited, but may be, for example, 6 to 60, 6 to 30 or 6 to 20. Examplesof the oxy group may include a methoxy group, an ethoxy group, ann-propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group,a hexyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group,a benzyloxy, etc., but the embodiment of the present disclosure is notlimited thereto.

The term “boron group” as used herein may refer to that a boron atom isbonded to the alkyl group or the aryl group as defined above. The borongroup includes an alkyl boron group and an aryl boron group. Examples ofthe boron group may include a dimethylboron group, a diethylboron group,a t-butylmethylboron group, a diphenylboron group, a phenylboron group,etc., but the embodiment of the present disclosure is not limitedthereto.

In the specification, the number of carbon atoms in an amine group isnot specifically limited, but may be 1 to 30. The amine group mayinclude an alkyl amine group and an aryl amine group. Examples of theamine group may include a methylamine group, a dimethylamine group, aphenylamine group, a diphenylamine group, a naphthylamine group, a9-methyl-anthracenylamine group, a triphenylamine group, etc., but theembodiment of the present disclosure is not limited thereto.

In the specification, the alkyl group in the alkylthio group, thealkylsulfoxy group, the alkylaryl group, the alkylamino group, the alkylboron group, the alkyl silyl group, and the alkyl amine group is thesame as the examples of the alkyl group described above.

In the specification, the aryl group in the aryloxy group, the arylthiogroup, the arylsulfoxy group, the arylamino group, the arylboron group,the arylsilyl group, the arylamine group is the same as the examples ofthe aryl group described above.

In the specification, a direct linkage may refer to a single bond. Insome embodiments, “

” herein refers to a position to be connected.

Hereinafter, a light emitting element according to an embodiment of thepresent disclosure will be described with reference to the drawings.

FIG. 1 is a plan view illustrating an embodiment of a display device DD.FIG. 2 is a cross-sectional view of the display device DD of theembodiment. FIG. 2 is a cross-sectional view illustrating a part takenalong the line I-I′ of FIG. 1 .

The display device DD may include a display panel DP and an opticallayer PP disposed on the display panel DP. The display panel DP mayinclude light emitting elements ED-1, ED-2, and ED-3. The display deviceDD may include a plurality of light emitting elements ED-1, ED-2, andED-3. The optical layer PP may be disposed on the display panel DP andcontrol reflected light in the display panel DP due to external light.The optical layer PP may include, for example, a polarization layer or acolor filter layer. In some embodiments, unlike the configurationillustrated in the drawing, the optical layer PP may not be provided inthe display device DD of an embodiment.

A base substrate BL may be disposed on the optical layer PP. The basesubstrate BL may be a member which provides a base surface on which theoptical layer PP is disposed. The base substrate BL may be a glasssubstrate, a metal substrate, a plastic substrate, etc. However, theembodiment of the present disclosure is not limited thereto, and thebase substrate BL may be an inorganic layer, an organic layer, or acomposite material layer. In some embodiments, unlike the configurationillustrated, the base substrate BL may not be provided.

The display device DD according to an embodiment may further include afilling layer. The filling layer may be disposed between a displayelement layer DP-ED and the base substrate BL. The filling layer may bean organic material layer. The filling layer may include at least one ofan acrylic-based resin, a silicone-based resin, or an epoxy-based resin.

The display panel DP may include a base layer BS, a circuit layer DP-CLprovided on the base layer BS, and the display element layer DP-ED. Thedisplay element layer DP-ED may include a pixel defining film PDL, thelight emitting elements ED-1, ED-2, and ED-3 disposed between portionsof the pixel defining film PDL, and an encapsulation layer TFE disposedon the light emitting elements ED-1, ED-2, and ED-3.

The base layer BS may be a member which provides a base surface on whichthe display element layer DP-ED is disposed. The base layer BS may be aglass substrate, a metal substrate, a plastic substrate, etc. However,the embodiment is not limited thereto, and the base layer BS may be aninorganic layer, an organic layer, or a composite material layer.

In an embodiment, the circuit layer DP-CL is disposed on the base layerBS, and the circuit layer DP-CL may include a plurality of transistors.Each of the transistors may include a control electrode, an inputelectrode, and an output electrode. For example, the circuit layer DP-CLmay include a switching transistor and a driving transistor for drivingthe light emitting elements ED-1, ED-2, and ED-3 of the display elementlayer DP-ED.

Each of the light emitting elements ED-1, ED-2, and ED-3 may have astructure of a light emitting element ED of an embodiment according toFIGS. 3 to 6 , which will be described in more detail later. Each of thelight emitting elements ED-1, ED-2 and ED-3 may include a firstelectrode EL1, a hole transport region HTR, emission layer(s) EML-R,EML-G and/or EML-B (e.g., a corresponding selected from among theemission layer EML-R, the emission layer EML-G, and the emission layerEML-B), an electron transport region ETR, and a second electrode EL2.

FIG. 2 illustrates an embodiment in which the emission layers EML-R,EML-G, and EML-B of the light emitting elements ED-1, ED-2, and ED-3 aredisposed in openings OH defined in the pixel defining film PDL, and thehole transport region HTR, the electron transport region ETR, and thesecond electrode EL2 are provided as a common layer in the entire lightemitting elements ED-1, ED-2, and ED-3. However, the embodiment of thepresent disclosure is not limited thereto, and unlike the configurationillustrated in FIG. 2 , the hole transport region HTR and the electrontransport region ETR in an embodiment may be provided by being patternedinside the openings OH defined in the pixel defining film PDL. Forexample, the hole transport region HTR, the emission layers EML-R,EML-G, and EML-B, and the electron transport region ETR of the lightemitting elements ED-1, ED-2, and ED-3 in an embodiment may be providedby being patterned through an inkjet printing method.

The encapsulation layer TFE may cover the light emitting elements ED-1,ED-2 and ED-3. The encapsulation layer TFE may seal the display elementlayer DP-ED. The encapsulation layer TFE may be a thin filmencapsulation layer. The encapsulation layer TFE may be formed as onelayer or by laminating a plurality of layers. The encapsulation layerTFE may include at least one insulation layer. The encapsulation layerTFE according to an embodiment may include at least one inorganic film(hereinafter, an encapsulation-inorganic film). The encapsulation layerTFE according to an embodiment may also include at least one organicfilm (hereinafter, an encapsulation-organic film) and at least oneencapsulation-inorganic film.

The encapsulation-inorganic film may protect the display element layerDP-ED from moisture/oxygen, and the encapsulation-organic film mayprotect the display element layer DP-ED from foreign substances such asdust particles. The encapsulation-inorganic film may include siliconnitride, silicon oxynitride, silicon oxide, titanium oxide, aluminumoxide, and/or the like, but the embodiment of the present disclosure isnot particularly limited thereto. The encapsulation-organic film mayinclude an acrylic-based compound, an epoxy-based compound, and/or thelike. The encapsulation-organic film may include a photopolymerizableorganic material, but the embodiment of the present disclosure is notparticularly limited thereto.

The encapsulation layer TFE may be disposed on the second electrode EL2and may be disposed to fill the opening OH.

Referring to FIGS. 1 and 2 , the display device DD may include anon-light emitting region NPXA and light emitting regions PXA-R, PXA-Gand PXA-B. The light emitting regions PXA-R, PXA-G and PXA-B may beregions in which light generated by the respective light emittingelements ED-1, ED-2 and ED-3 is emitted. The light emitting regionsPXA-R, PXA-G, and PXA-B may be spaced apart from one another on a plane(e.g., in a plan view).

Each of the light emitting regions PXA-R, PXA-G, and PXA-B may be aregion divided by the pixel defining film PDL. The non-light emittingregions NPXA may be regions between the adjacent light emitting regionsPXA-R, PXA-G, and PXA-B, which correspond to portions of the pixeldefining film PDL. In some embodiments, in the specification, the lightemitting regions PXA-R, PXA-G, and PXA-B may each correspond to arespective pixel. The pixel defining film PDL may divide or define thelight emitting elements ED-1, ED-2, and ED-3. The emission layers EML-R,EML-G and EML-B of the light emitting elements ED-1, ED-2 and ED-3 maybe disposed in openings OH defined in the pixel defining film PDL andseparated from one another.

The light emitting regions PXA-R, PXA-G and PXA-B may be divided into aplurality of groups according to the color of light generated from thelight emitting elements ED-1, ED-2 and ED-3. In the display device DD ofan embodiment shown in FIGS. 1 and 2 , three light emitting regionsPXA-R, PXA-G, and PXA-B which emit red light, green light, and bluelight, respectively, are illustrated. For example, the display device DDof an embodiment may include the red light emitting region PXA-R, thegreen light emitting region PXA-G, and the blue light emitting regionPXA-B that are separated from one another.

In the display device DD according to an embodiment, the plurality oflight emitting elements ED-1, ED-2 and ED-3 may be to emit light (e.g.,light beams) having wavelengths different from one another. For example,in an embodiment, the display device DD may include a first lightemitting element ED-1 that emits red light, a second light emittingelement ED-2 that emits green light, and a third light emitting elementED-3 that emits blue light. For example, the red light emitting regionPXA-R, the green light emitting region PXA-G, and the blue lightemitting region PXA-B of the display device DD may correspond to thefirst light emitting element ED-1, the second light emitting elementED-2, and the third light emitting element ED-3, respectively.

However, the embodiment of the present disclosure is not limitedthereto, and the first to third light emitting elements ED-1, ED-2, andED-3 may be to emit light (e.g., light beams) in substantially the samewavelength range or at least one light emitting element may be to emit alight (e.g., light beam) in a wavelength range different from theothers. For example, the first to third light emitting elements ED-1,ED-2, and ED-3 may all emit blue light.

The light emitting regions PXA-R, PXA-G, and PXA-B in the display deviceDD according to an embodiment may be arranged in a stripe form.Referring to FIG. 1 , the plurality of red light emitting regions PXA-Rmay be arranged with one another along a second directional axis DR2,the plurality of green light emitting regions PXA-G may be arranged withone another along the second directional axis DR2, and the plurality ofblue light emitting regions PXA-B may be arranged with one another alongthe second directional axis DR2. In some embodiments, the red lightemitting region PXA-R, the green light emitting region PXA-G, and theblue light emitting region PXA-B may also be alternately arranged inthis order along a first directional axis DR1.

FIGS. 1 and 2 illustrate that all the light emitting regions PXA-R,PXA-G, and PXA-B have similar area, but the embodiment of the presentdisclosure is not limited thereto. Thus, the light emitting regionsPXA-R, PXA-G, and PXA-B may have different areas from one anotheraccording to the wavelength range of the emitted light. In this case,the areas of the light emitting regions PXA-R, PXA-G, and PXA-B mayrefer to areas when viewed on a plane defined by the first directionalaxis DR1 and the second directional axis DR2 (e.g., in a plan view).

In some embodiments, an arrangement form of the light emitting regionsPXA-R, PXA-G, and PXA-B is not limited to the configuration illustratedin FIG. 1 , and the order in which the red light emitting region PXA-R,the green light emitting region PXA-G, and the blue light emittingregion PXA-B are arranged may be provided in one or more suitablecombinations according to the characteristics of display qualityrequired in the display device DD. For example, the arrangement form ofthe light emitting regions PXA-R, PXA-G, and PXA-B may be a PENTILE®arrangement form (e.g., an RGBG matrix, RGBG structure, or RGBG matrixstructure) or a Diamond Pixel™ arrangement form. PENTILE® and DiamondPixel™ are both trademarks of Samsung Display Co., Ltd.

In some embodiments, the areas of the light emitting regions PXA-R,PXA-G, and PXA-B may be different from one another. For example, in anembodiment, the area of the green light emitting region PXA-G may besmaller than that of the blue light emitting region PXA-B, but theembodiment of the present disclosure is not limited thereto.

Hereinafter, FIGS. 3 to 6 are cross-sectional views schematicallyillustrating light emitting elements according to embodiments. Each ofthe light emitting elements ED according to embodiments may include afirst electrode EL1, a second electrode EL2 facing the first electrodeEL1, and at least one functional layer disposed between the firstelectrode EU and the second electrode EL2. The light emitting element EDof an embodiment may include a polycyclic compound of an embodiment,which will be described in more detail below, in at least one functionallayer.

Each of the light emitting elements ED may include, as the at least onefunctional layer, a hole transport region HTR, an emission layer EML,and an electron transport region ETR that are sequentially stacked inthe stated order. For example, each of the light emitting elements ED ofembodiments may include the first electrode EL1, the hole transportregion HTR, the emission layer EML, the electron transport region ETR,and the second electrode EL2 that are sequentially stacked in the statedorder.

The light emitting element ED of an embodiment may include thepolycyclic compound of an embodiment, which will be described in moredetail below, in the emission layer EML. However, the embodiment of thepresent disclosure is not limited thereto, and the light emittingelement ED: may include the polycyclic compound according to anembodiment, which will be described in more detail below, in the holetransport region HTR from among the plurality of functional layersdisposed between the first electrode EL1 and the second electrode EL2;or may include the polycyclic compound according to an embodiment, whichwill be described in more detail below, in a capping layer CPL disposedon the second electrode EL2, as well as in the emission layer EML andthe electron transport region ETR.

Compared with FIG. 3 , FIG. 4 illustrates a cross-sectional view of alight emitting element ED of an embodiment, in which a hole transportregion HTR includes a hole injection layer HIL and a hole transportlayer HTL, and an electron transport region ETR includes an electroninjection layer EIL and an electron transport layer ETL. In someembodiments, compared with FIG. 3 , FIG. 5 illustrates a cross-sectionalview of a light emitting element ED of an embodiment, in which a holetransport region HTR includes a hole injection layer HIL, a holetransport layer HTL, and an electron blocking layer EBL, and an electrontransport region ETR includes an electron injection layer EIL, anelectron transport layer ETL, and a hole blocking layer HBL. Comparedwith FIG. 4 , FIG. 6 illustrates a cross-sectional view of a lightemitting element ED of an embodiment including a capping layer CPLdisposed on a second electrode EL2.

In the light emitting element ED according to an embodiment, the firstelectrode EL1 has suitable conductivity (e.g., is a conductor). Thefirst electrode EL1 may be formed of a metal material, a metal alloy, ora conductive compound. The first electrode EL1 may be an anode or acathode. However, the embodiment of the present disclosure is notlimited thereto. In some embodiments, the first electrode EL1 may be apixel electrode. The first electrode EL1 may be a transmissiveelectrode, a transflective electrode, or a reflective electrode. Thefirst electrode EU may include at least one selected from among Ag, Mg,Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, andZn, a compound of two or more selected therefrom (e.g., from amongthese), a mixture of two or more therefrom (e.g., selected from amongthese), or an oxide thereof.

When the first electrode EL1 is the transmissive electrode, the firstelectrode EL1 may include a transparent metal oxide such as indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and/or indiumtin zinc oxide (ITZO). When the first electrode EL1 is the transflectiveelectrode or the reflective electrode, the first electrode EL1 mayinclude Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca (astacked structure of LiF and Ca), LiF/AI (a stacked structure of LiF andAl), Mo, Ti, W, or a compound or mixture thereof (e.g., a mixture of Agand Mg). In some embodiments, the first electrode EU may have amultilayer structure including a reflective film or a transflective filmformed of the above-described materials, and a transparent conductivefilm formed of ITO, IZO, ZnO, ITZO, etc. For example, the firstelectrode EL1 may have a three-layer structure of ITO/Ag/ITO, but theembodiment of the present disclosure is not limited thereto. In someembodiments, the first electrode EL1 may include the above-describedmetal material(s), combination(s) of at least two metal material(s) ofthe above-described metal materials, oxide(s) of the above-describedmetal material(s), and/or the like. The thickness of the first electrodeEL1 may be from about 700 Å to about 10,000 Å. For example, thethickness of the first electrode EL1 may be from about 1,000 Å to about3,000 Å.

The hole transport region HTR is provided on the first electrode EL1.The hole transport region HTR may include at least one of a holeinjection layer HIL, a hole transport layer HTL, a buffer layer or anemission-auxiliary layer, and/or an electron blocking layer EBL. Thethickness of the hole transport region HTR may be, for example, fromabout 50 Å to about 15,000 Å.

The hole transport region HTR may have a single layer formed of a singlematerial, a single layer formed of a plurality of different materials,or a multilayer structure including a plurality of layers formed of aplurality of different materials.

For example, the hole transport region HTR may have a single layerstructure of the hole injection layer HIL or the hole transport layerHTL, or may have a single layer structure formed of a hole injectionmaterial and a hole transport material. In some embodiments, the holetransport region HTR may have a single layer structure formed of aplurality of different materials, or a structure in which a holeinjection layer HIL/hole transport layer HTL, a hole injection layerHIL/hole transport layer HTL/buffer layer, a hole injection layerHIL/buffer layer, a hole transport layer HTL/buffer layer, or a holeinjection layer HIL/hole transport layer HTL/electron blocking layerEBL, that are stacked in the respective stated order from the firstelectrode EU, but the embodiment of the present disclosure is notlimited thereto.

The hole transport region HTR may be formed utilizing one or moresuitable methods such as a vacuum deposition method, a spin coatingmethod, a cast method, a Langmuir-Blodgett (LB) method, an inkjetprinting method, a laser printing method, and/or a laser induced thermalimaging (LITI) method.

The hole transport region HTR may include a compound represented byFormula H-1:

In Formula H-1 above, L₁ and L₂ may each independently be a directlinkage, a substituted or unsubstituted arylene group having 6 to 30ring-forming carbon atoms, or a substituted or unsubstitutedheteroarylene group having 2 to 30 ring-forming carbon atoms. n1 and n2may each independently be an integer of 0 to 10. In some embodiments,when n1 or n2 is an integer of 2 or more, a plurality of Li's and/or aplurality of L₂'s may each independently be a substituted orunsubstituted arylene group having 6 to 30 ring-forming carbon atoms, ora substituted or unsubstituted heteroarylene group having 2 to 30ring-forming carbon atoms.

In Formula H-1, Ar₁₁ and Ar₁₂ may each independently be a substituted orunsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or asubstituted or unsubstituted heteroaryl group having 2 to 30ring-forming carbon atoms. In some embodiments, in Formula H-1, Ar₁₃ maybe a substituted or unsubstituted aryl group having 6 to 30 ring-formingcarbon atoms.

The compound represented by Formula H-1 above may be a monoaminecompound (e.g., a compound including a single amine group). In someembodiments, the compound represented by Formula H-1 above may be adiamine compound in which at least one selected from among Ar₁₁ to Ar₁₃includes an amine group as a substituent. In some embodiments, thecompound represented by Formula H-1 above may be a carbazole-basedcompound including a substituted or unsubstituted carbazole group in atleast one of Ar₁₁ or Ar₁₂, or a fluorene-based compound including asubstituted or unsubstituted fluorene group in at least one of Aril orAr₁₂.

The compound represented by Formula H-1 may be represented by any oneselected from among the compounds of Compound Group H. However, thecompounds listed in Compound Group H are examples, and the compoundsrepresented by Formula H-1 are not limited to those represented byCompound Group H:

The hole transport region HTR may further include a phthalocyaninecompound such as copper phthalocyanine;N¹,N^(1′)-([1,1′-biphenyl]-4,4′-diyl)bis(N¹-phenyl-N⁴,N⁴-di-m-tolylbenzene-1,4-diamine)(DNTPD), 4,4′,4″-[tris(3-methylphenyl)phenylamino] triphenylamine(m-MTDATA), 4,4′4″-tris(N,N-diphenylamino)triphenylamine (TDATA),4,4′,4″-tris[N(2-naphthyl)-N-phenylamino]-triphenylamine (2-TNATA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), polyaniline/camphorsulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate)(PANI/PSS), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB(orNPD)), triphenylamine-containing polyetherketone (TPAPEK),4-isopropyl-4′-methyldiphenyliodonium[tetrakis(pentafluorophenyl)borate], dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN), etc.

The hole transport region HTR may include a carbazole-based derivativesuch as N-phenyl carbazole and/or polyvinyl carbazole, a fluorene-basedderivative, a triphenylamine-based derivative such asN,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD)and/or 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB),4,4′-cyclohexylidene bis[N,N-bis(4-methylphenyl]benzenamine] (TAPC),4,4′-bis[N,N-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD),1,3-bis(N-carbazolyl)benzene (mCP), etc.

In some embodiments, the hole transport region HTR may include9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi),9-phenyl-9H-3,9′-bicarbazole (CCP),1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene (mDCP), etc.

The hole transport region HTR may include the above-described compoundsof the hole transport region in at least one of a hole injection layerHIL, a hole transport layer HTL, or an electron blocking layer EBL.

The thickness of the hole transport region HTR may be from about 100 Åto about 10,000 Å, for example, from about 100 Å to about 5,000 Å. Whenthe hole transport region HTR includes the hole injection layer HIL, thehole injection layer HIL may have, for example, a thickness of about 30Å to about 1,000 Å. When the hole transport region HTR includes the holetransport layer HTL, the hole transport layer HTL may have a thicknessof about 30 Å to about 1,000 Å. For example, when the hole transportregion HTR includes the electron blocking layer EBL, the electronblocking layer EBL may have a thickness of about 10 Å to about 1,000 Å.When the thicknesses of the hole transport region HTR, the holeinjection layer HIL, the hole transport layer HTL and the electronblocking layer EBL satisfy the above-described ranges, satisfactory,suitable, and/or desired hole transport properties may be achievedwithout a substantial increase in driving voltage.

The hole transport region HTR may further include a charge generatingmaterial to increase conductivity in addition to the above-describedmaterials. The charge generating material may be dispersed uniformly ornon-uniformly in the hole transport region HTR. The charge generatingmaterial may be, for example, a p-dopant. The p-dopant may include atleast one of a halogenated metal (e.g., metal halide) compound, aquinone derivative, a metal oxide, or a cyano group-containing compound,but the embodiment of the present disclosure is not limited thereto. Forexample, the p-dopant may include a metal halide compound such as Culand/or RbI, a quinone derivative such as tetracyanoquinodimethane (TCNQ)and/or 2,3,5,6-tetrafluoro-7,7, 8,8-tetracyanoquinodimethane (F4-TCNQ),a metal oxide such as tungsten oxide and/or molybdenum oxide, a cyanogroup-containing compound such as dipyrazino[2,3-f: 2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN) and/or4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylidene]cyclopropylidene]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile (NDP9), etc., but theembodiment of the present disclosure is not limited thereto.

As described above, the hole transport region HTR may further include atleast one of the buffer layer or the electron blocking layer EBL inaddition to the hole injection layer HIL and the hole transport layerHTL. The buffer layer may compensate for a resonance distance accordingto the wavelength of light emitted from the emission layer EML and maythus increase light emission efficiency. A material that may becontained in the hole transport region HTR may be utilized as a materialto be contained in the buffer layer. The electron blocking layer EBL isa layer that serves to prevent or reduce the electron injection from theelectron transport region ETR to the hole transport region HTR.

The emission layer EML is provided on the hole transport region HTR. Theemission layer EML may have a thickness of, for example, about 100 Å toabout 1,000 Å or about 100 Å to about 300 Å. The emission layer EML mayhave a single layer formed of a single material, a single layer formedof a plurality of different materials, or a multilayer structure havinga plurality of layers formed of a plurality of different materials.

In the light emitting element ED according to an embodiment, theemission layer EML may include a polycyclic compound of an embodiment.The polycyclic compound of an embodiment may be a fused polycycliccompound including a structure in which a silyl group is fused with acarbazole skeleton. For example, the polycyclic compound of anembodiment may be a fused polycyclic compound in which a carbazole and atriphenylsilyl group are fused with each other.

The polycyclic compound in an embodiment may be represented byFormula 1. The polycyclic compound represented by Formula 1 may have amolecular weight of about 500 or more:

In Formula 1, R₁ and R₂ may each independently be a hydrogen atom, adeuterium atom, a cyano group, a substituted or unsubstituted silylgroup, a substituted or unsubstituted alkyl group having 1 to 20 carbonatoms, a substituted or unsubstituted cycloalkyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms. For example, R₁ and R₂ may eachindependently be a substituted or unsubstituted alkyl group having 1 to10 carbon atoms, or a substituted or unsubstituted aryl group having 6to 20 ring-forming carbon atoms. For example, R₁ and R₂ may eachindependently be a hydrogen atom, a deuterium atom, or a substituted orunsubstituted phenyl group. However, the embodiment of the presentdisclosure is not limited thereto.

In Formula 1, a and b may each independently be an integer of 0 to 5.For example, the case where a is 0 may be the same as the case where ais 1 and R₁ is a hydrogen atom. The case where b is 0 may be the same asthe case where b is 1 and R₂ is a hydrogen atom.

When each of a and b is an integer of 2 or more, a plurality of R₁'s andR₂'s may each be the same or different. For example, when a is 2, twoR₁'s may be the same as or different from each other. In addition, whenb is 2, two R₂'s may be the same as or different from each other.

In Formula 1, R₃ and R₄ may each independently be a hydrogen atom, adeuterium atom, or a substituent represented by Formula 2 or Formula 3.In the polycyclic compound represented by Formula 1 of an embodiment, atleast one of R₃ or R₄ may be a substituent represented by Formula 2 orFormula 3. For example, the polycyclic compound of an embodiment mayinclude one substituent represented by Formula 2 or one substituentrepresented by Formula 3. However, the embodiment of the presentdisclosure is not limited thereto, and the polycyclic compound of anembodiment may include two or more substituents represented by Formula 2and/or Formula 3.

In Formula 2 and Formula 3,

represents a linking position, and may be a part bonded to an aromaticring in Formula 1.

In Formula 2 and Formula 3, R₅ to R₇ may each independently be ahydrogen atom, a deuterium atom, a cyano group, a substituted orunsubstituted silyl group, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylgroup having 3 to 20 ring-forming carbon atoms, a substituted orunsubstituted heterocycloalkyl group having 3 to 20 ring-forming carbonatoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms, or may be bonded to an adjacent groupto form a ring.

In an embodiment, R₅ to R₇ may each independently be a hydrogen atom, adeuterium atom, or a substituent represented by any one selected fromamong R-1 to R-5. However, the embodiment of the present disclosure isnot limited thereto. In R-1 to R-5, “

” may be a part bonded to a benzene ring in Formula 2 or Formula 3:

In Formula 2, e and f may each independently be an integer of 0 to 4.For example, the case where e is 0 may refer to that the substituentrepresented by Formula 2 is not substituted with R₅, and may be the sameas the case where e is 1 and R₅ is a hydrogen atom. In addition, such anexample description may be equally applied to the case where f is Of.

When each of a and f is an integer of 2 or more, a plurality of R₅'s andR₆'s may each be the same or different. For example, when a is 2, twoR₅'s may be the same as or different from each other. In addition, whenf is 2, two R₆'s may be the same as or different from each other.

In Formula 2, g is 0 or 1, and when g is 1, X may be a direct linkage.For example, when g is 0, the two benzene rings linked to the nitrogenatom in Formula 2 may not be linked via X. That is, when g is 0, thesubstituent represented by Formula 2 may include a diphenylamine moietyand not a carbazole moiety. In addition, the case where g is 1 may referto that the two benzene rings linked to the nitrogen atom in Formula 2is linked via a direct linkage to form a fused ring. That is, when g is1, the substituent represented by Formula 2 may include a carbazolemoiety.

For example, when g in Formula 2 is 0, the substituent represented byFormula 2 may be represented by Formula 2-2. When g in Formula 2 is 1,the substituent represented by Formula 2 may be represented by Formula2-1:

In Formula 2-1 and Formula 2-2, the same description of R₅ and R₆ asdescribed in Formula 2 above may be applied to R_(5i) to R_(6i). Forexample, R_(5i) and R_(6i) may each independently be a hydrogen atom, adeuterium atom, a substituted or unsubstituted silyl group, asubstituted or unsubstituted alkyl group having 1 to 10 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 20 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 20 ring-forming carbon atoms. For example, R_(5i) to R_(6i) mayeach independently be a hydrogen atom, a deuterium atom, or asubstituent represented by any one selected from among R-1 to R-5.However, the embodiment of the present disclosure is not limitedthereto.

In Formula 2-1 and Formula 2-2, the same as described in Formula 2 maybe applied to e and f.

In Formula 3, h is an integer of 0 to 5. For example, the case where his 0 may refer to that the substituent represented by Formula 3 is notsubstituted with R₇, and may be the same as the case where h is 1 and R₇is a hydrogen atom. When h is an integer of 2 or more, a plurality ofR₇'s may be the same as or different from each other. For example, whenh is 2, two R₇'s may be the same as or different from each other.

In an embodiment, the polycyclic compound represented by Formula 1 maybe represented by Formula 1-1 or Formula 1-2. The polycyclic compoundrepresented by Formula 1-1 of an embodiment corresponds to the casewhere R₁ is specified in the polycyclic compound represented by Formula1, and any one selected from among R₃ and R₄ is a substituentrepresented by Formula 2. The polycyclic compound represented by Formula1-2 of an embodiment corresponds to the case where R₁ is specified inthe polycyclic compound represented by Formula 1, and any one selectedfrom among R₃ and R₄ is a substituent represented by Formula 3.

In Formula 1-1 and Formula 1-2, the same description of R₁ as describedin Formula 1 above may be applied to R_(1i). For example, Ru may be ahydrogen atom, a deuterium atom, a substituted or unsubstituted alkylgroup having 1 to 10 carbon atoms, or a substituted or unsubstitutedaryl group having 6 to 20 ring-forming carbon atoms.

In Formula 1-1 and Formula 1-2, the same as described in Formula 1 toFormula 3 above may be applied to R₅ to R₇, a, e, f, and h.

In an embodiment, the polycyclic compound represented by Formula 1-1 maybe represented by Formula 1-1-1 or Formula 1-1-2. Formula 1-1-1 andFormula 1-1-2 represent that the bonding position of the carbazolemoiety in Formula 1-1 is specified. In addition, Formula 1-1-1 andFormula 1-1-2 may respectively represent the case where R₃ in Formula 1is a substituent represented by Formula 2 and R₄ in Formula 1 is asubstituent represented by Formula 2.

In Formula 1-1-1 and Formula 1-1-2, the same as described in Formula 1-1and Formula 2 above may be applied to R_(1i), R₅, R₆, a, e, and f.

In an embodiment, the polycyclic compound represented by Formula 1-2 maybe represented by Formula 1-2-1 or Formula 1-2-2. Formula 1-2-1 andFormula 1-2-2 represent that the bonding position of the substituted orunsubstituted phenyl group in Formula 1-2 is specified. In addition,Formula 1-2-1 and Formula 1-2-2 may respectively represent the casewhere R₃ in Formula 1 is a substituent represented by Formula 3 and R₄in Formula 1 is a substituent represented by Formula 3.

In Formula 1-2-1 and Formula 1-2-2, the same as described in Formula 1-2and Formula 3 above may be applied to R_(1i), R₇, a and h.

The polycyclic compound represented by Formula 1 of an embodiment may berepresented by any one selected from among the compounds represented byCompound Group 1. The light emitting element ED of an embodiment mayinclude at least one polycyclic compound selected from among thecompounds represented by Compound Group 1 in the emission layer EML.

The polycyclic compound of an embodiment includes a skeleton in which atriphenylsilane group, which may cause steric hindrance effects on acarbazole group, is fused with the carbazole group, may reduce thegeneration of exciplex due to the intermolecular interaction, and thusmay exhibit excellent or suitable color purity when utilized as anemission layer material, and may have a relatively high lowest tripletexcitation energy level (T1 level).

The polycyclic compound represented by Formula 1 of an embodiment may bea luminescent material having a luminescence center wavelength in awavelength region of about 430 nm to about 480 nm. The emission layerEML of the light emitting element ED may include the polycyclic compoundrepresented by Formula 1 of an embodiment, thereby emitting blue light.For example, the emission layer EML of the light emitting element ED ofan embodiment may be to emit blue light in a region of about 480 nm orless. However, the embodiment of the present disclosure is not limitedthereto, and the emission layer EML may be to emit green light or redlight.

In some embodiments, the emission layer EML includes a host and adopant, and may include the above-described polycyclic compound as ahost. The polycyclic compound represented by Formula 1 of an embodimentmay be a host material of the emission layer.

For example, the emission layer EML in the light emitting element ED ofan embodiment may include a host for emitting phosphorescence and adopant for emitting phosphorescence, and may include the above-describedpolycyclic compound of an embodiment as a host for emittingphosphorescence. In some embodiments, the emission layer EML in thelight emitting element ED of an embodiment may include a host foremitting fluorescence and a dopant for emitting fluorescence, and mayinclude the above-described polycyclic compound of an embodiment as ahost for emitting fluorescence.

The emission layer EML in the light emitting element ED of an embodimentmay include a host for emitting delayed fluorescence and a dopant foremitting delayed fluorescence, and may include the above-describedpolycyclic compound of an embodiment as a host for emitting delayedfluorescence. The emission layer EML in the light emitting element ED ofan embodiment may include a host for emitting blue thermally activateddelayed fluorescence (TADF) and a dopant for emitting blue TADF, and mayinclude the above-described polycyclic compound of an embodiment as ahost for emitting blue TADF. The emission layer EML may include at leastone selected from among the polycyclic compounds represented by CompoundGroup 1 as described above as a host material of the emission layer.

In some embodiments, in the light emitting element ED of an embodiment,the emission layer EML may further include a suitable material. Theemission layer EML may include one or more anthracene derivatives,pyrene derivatives, fluoranthene derivatives, chrysene derivatives,dehydrobenzanthracene derivatives, and/or triphenylene derivatives. Inan embodiment, the emission layer EML may include one or more anthracenederivatives and/or pyrene derivatives.

In each light emitting element ED of embodiments illustrated in FIGS. 3to 6 , the emission layer EML may include a host and a dopant, and theemission layer EML may include a compound represented by Formula E-1.The compound represented by Formula E-1 may be utilized as afluorescence host material or a delayed fluorescence host material.

In Formula E-1, R₃₁ to R₄₀ may each independently be a hydrogen atom, adeuterium atom, a halogen atom, a substituted or unsubstituted silylgroup, a substituted or unsubstituted thio group, a substituted orunsubstituted oxy group, a substituted or unsubstituted alkyl grouphaving 1 to 10 carbon atoms, a substituted or unsubstituted alkenylgroup having 1 to 10 carbon atoms, a substituted or unsubstituted arylgroup having 6 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,and/or may be bonded to an adjacent group to form a ring. In someembodiments, R₃₁ to R₄₀ may be bonded to an adjacent group to form asaturated hydrocarbon ring or an unsaturated hydrocarbon ring, asaturated heterocycle, or an unsaturated heterocycle.

In Formula E-1, c and d may each independently be an integer of 0 to 5.

The compound represented by Formula E-1 may be any one selected fromamong the compounds represented by Compound Group E-1:

In an embodiment, the emission layer EML may further include a compoundrepresented by Formula E-2a or Formula E-2b. The compound represented byFormula E-2a or Formula E-2b may be utilized as a phosphorescence hostmaterial or a delayed fluorescence host material.

In Formula E-2a, a may be an integer of 0 to 10, and La may be a directlinkage, a substituted or unsubstituted arylene group having 6 to 30ring-forming carbon atoms, or a substituted or unsubstitutedheteroarylene group having 2 to 30 ring-forming carbon atoms. In someembodiments, when a is an integer of 2 or more, a plurality of La's mayeach independently be a substituted or unsubstituted arylene grouphaving 6 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heteroarylene group having 2 to 30 ring-forming carbonatoms.

In addition, in Formula E-2a, A₁ to A₅ may each independently be N orCR_(i). R_(a) to R_(i) may each independently be a hydrogen atom, adeuterium atom, a substituted or unsubstituted amine group, asubstituted or unsubstituted thio group, a substituted or unsubstitutedoxy group, a substituted or unsubstituted oxide group, a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted alkenyl group having 2 to 20 carbon atoms, a substitutedor unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, ora substituted or unsubstituted heteroaryl group having 2 to 30ring-forming carbon atoms, and/or may be bonded to an adjacent group toform a ring. In an embodiment, R_(a) to R_(i) may be bonded to anadjacent group to form a hydrocarbon ring or a heterocycle containing N,O, S, etc. as a ring-forming atom.

In some embodiments, in Formula E-2a, two or three selected from amongA₁ to A₅ may be N, and the rest (e.g., a remainder from among A₁ to A₅)may be CR_(i).

In Formula E-2b, Cbz1 and Cbz2 may each independently be anunsubstituted carbazole group, or a carbazole group substituted with anaryl group having 6 to 30 ring-forming carbon atoms. L_(b) may be adirect linkage, a substituted or unsubstituted arylene group having 6 to30 ring-forming carbon atoms, or a substituted or unsubstitutedheteroarylene group having 2 to 30 ring-forming carbon atoms. In someembodiments, b may be an integer of 0 to 10, and when b is an integer of2 or more, a plurality of L_(b)'s may each independently be asubstituted or unsubstituted arylene group having 6 to 30 ring-formingcarbon atoms, or a substituted or unsubstituted heteroarylene grouphaving 2 to 30 ring-forming carbon atoms.

The compound represented by Formula E-2a or Formula E-2b may berepresented by any one selected from among the compounds of CompoundGroup E-2. However, the compounds listed in Compound Group E-2 areexamples, and the compound represented by Formula E-2a or Formula E-2bis not limited to those represented in Compound Group E-2.

The emission layer EML may further include a material suitable in theart as a host material. For example, the emission layer EML may include,as a host material, at least one ofbis(4-(9H-carbazol-9-yl)phenyl)diphenylsilane (BCPDS),(4-(1-(4-(diphenylamino)phenyl)cyclohexyl)phenyl)diphenyl-phosphineoxide (POPCPA), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO),4,4′-bis(N-carbazolyI)-1,1′-biphenyl (CBP),1,3-bis(carbazol-9-yl)benzene (mCP),2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF),4,4′,4″-tris(carbazol-9-yl)-triphenylamine (TCTA), or1,3,5-tris(1-phenyl-1H-benzo[d]imidazole-2-yl)benzene (TPBi). However,the embodiment of the present disclosure is not limited thereto, forexample, tris(8-hydroxyquinolino)aluminum (Alq3),9,10-di(naphthalene-2-yl)anthracene (ADN),2-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), distyrylarylene(DSA), 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl (CDBP),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2),hexaphenylcyclotrisiloxane (DPSiO₃), octaphenylcyclotetra siloxane(DPSiO₄), etc. may be utilized as a host material.

The emission layer EML may further include a compound represented byFormula M-a or Formula M-b. The compound represented by Formula M-a orFormula M-b may be utilized as a phosphorescent dopant material. In someembodiments, the compound represented by Formula M-a or Formula M-b inan embodiment may be utilized as an auxiliary dopant material.

In Formula M-a above, Y₁ to Y₄ and Z₁ to Z₄ may each independently beCR₁ or N, and R₁ to R₄ may each independently be a hydrogen atom, adeuterium atom, a substituted or unsubstituted amine group, asubstituted or unsubstituted thio group, a substituted or unsubstitutedoxy group, a substituted or unsubstituted alkyl group having 1 to 20carbon atoms, a substituted or unsubstituted alkenyl group having 2 to20 carbon atoms, a substituted or unsubstituted aryl group having 6 to30 ring-forming carbon atoms, or a substituted or unsubstitutedheteroaryl group having 2 to 30 ring-forming carbon atoms, and/or may bebonded to an adjacent group to form a ring. In Formula M-a, m may be 0or 1, and n may be 2 or 3. In Formula M-a, when m is 0, n is 3, and whenm is 1, n is 2.

The compound represented by Formula M-a may be represented by any oneselected from among Compound M-a1 to Compound M-a25. However, CompoundsM-a1 to M-a25 are examples, and the compound represented by Formula M-ais not limited to those represented by Compounds M-a1 to M-a25.

Compound M-a1 and Compound M-a2 may be utilized as a red dopantmaterial, and Compound M-a3 to Compound M-a7 may be utilized as a greendopant material.

In Formula M-b, Q₁ to Q₄ may each independently be C or N, and C1 to C4may each independently be a substituted or unsubstituted hydrocarbonring having 5 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heterocycle having 2 to 30 ring-forming carbon atoms. L₂₁to L₂₄ may each independently be a direct linkage,

a substituted or unsubstituted divalent alkyl group having 1 to 20carbon atoms, a substituted or unsubstituted arylene group having 6 to30 ring-forming carbon atoms, or a substituted or unsubstitutedheteroarylene group having 2 to 30 ring-forming carbon atoms, and e1 toe4 may each independently be 0 or 1. R₃₁ to R₃₉ may each independentlybe a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, asubstituted or unsubstituted amine group, a substituted or unsubstitutedalkyl group having 1 to 20 carbon atoms, a substituted or unsubstitutedaryl group having 6 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,and/or bonded to an adjacent group to form a ring, and d1 to d4 may eachindependently be an integer of 0 to 4.

The compound represented by Formula M-b may be utilized as a bluephosphorescent dopant or a green phosphorescent dopant.

The compound represented by Formula M-b may be represented by any oneselected from among the compounds below. However, the compounds beloware examples, and the compound represented by Formula M-b is not limitedto those represented by the compounds below.

In the compounds, R, R₃₈, and R₃₉ may each independently be a hydrogenatom, a deuterium atom, a halogen atom, a cyano group, a substituted orunsubstituted amine group, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

The emission layer EML may further include a compound represented by anyone selected from among Formula F-a to Formula F-c. The compoundrepresented by Formula F-a or Formula F-c may be utilized as afluorescence dopant material.

In Formula F-a above, two groups selected from among R_(a) to R_(j) mayeach independently be substituted with *—NAr₁Ar₂ The others (e.g., therest of R_(a) to R_(j)), which are not substituted with *—NAr₁Ar₂ amongR_(a) to R_(j) may each independently be a hydrogen atom, a deuteriumatom, a halogen atom, a cyano group, a substituted or unsubstitutedamine group, a substituted or unsubstituted alkyl group having 1 to 20carbon atoms, a substituted or unsubstituted aryl group having 6 to 30ring-forming carbon atoms, or a substituted or unsubstituted heteroarylgroup having 2 to 30 ring-forming carbon atoms. In *—NAr₁Ar₂ An and Aremay each independently be a substituted or unsubstituted aryl grouphaving 6 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.For example, at least one of An or Are may be a heteroaryl groupcontaining 0 or S as a ring-forming atom.

In Formula F-b above, R_(a) and R_(b) may each independently be ahydrogen atom, a deuterium atom, a substituted or unsubstituted alkylgroup having 1 to 20 carbon atoms, a substituted or unsubstitutedalkenyl group having 2 to 20 carbon atoms, a substituted orunsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or asubstituted or unsubstituted heteroaryl group having 2 to 30ring-forming carbon atoms, and/or may be bonded to an adjacent group toform a ring. In an embodiment, An to Ara may each independently be asubstituted or unsubstituted aryl group having 6 to 30 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 30 ring-forming carbon atoms.

In Formula F-b, U and V may each independently be a substituted orunsubstituted hydrocarbon ring having 5 to 30 ring-forming carbon atoms,or a substituted or unsubstituted heterocycle having 2 to 30ring-forming carbon atoms.

In Formula F-b, the number of rings represented by U and V may eachindependently be 0 or 1. For example, in Formula F-b, when the number ofU or V is 1, one ring indicated by U or V forms a condensed ring at thedesignated part, and when the number of U or V is 0, it indicates thatno ring indicated by U or V is present. For example, when the number ofU is 0 and the number of V is 1, or when the number of U is 1 and thenumber of V is 0, the fused ring having a fluorene core in Formula F-bmay be a cyclic compound having four rings. In addition, when eachnumber of U and V is 0, the fused ring in Formula F-b may be a cycliccompound having three rings. In addition, when each number of U and V is1, the fused ring having a fluorene core in Formula F-b may be a cycliccompound having five rings.

In Formula F-c, A₁ and A₂ may each independently be 0, S, Se, or NR_(m),and R_(m) may be a hydrogen atom, a deuterium atom, a substituted orunsubstituted alkyl group having 1 to 20 carbon atoms, a substituted orunsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or asubstituted or unsubstituted heteroaryl group having 2 to 30ring-forming carbon atoms. R₁ to R₁₁ may each independently be ahydrogen atom, a deuterium atom, a halogen atom, a cyano group, asubstituted or unsubstituted amine group, a substituted or unsubstitutedboryl group, a substituted or unsubstituted oxy group, a substituted orunsubstituted thio group, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,and/or bonded to an adjacent group to form a ring.

In Formula F-c, A₁ and A₂ may each independently be bonded tosubstituents of an adjacent ring to form a condensed ring. For example,when A₁ and A₂ may each independently be NR_(m), A₁ may be bonded to R₄or R₅ to form a ring. In some embodiments, A₂ may be bonded to R₇ or R₈to form a ring.

In an embodiment, the emission layer EML may include, as a suitabledopant material, a styryl derivative (e.g.,1,4-bis[2-(3-N-ethylcarbazoryl)vinyl]benzene (BCzVB),4-(di-p-tolylamino)-4′-[(di-p-tolylamino)styryl]stilbene (DPAVB), and/orN-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine (N-BDAVBi)),4,4′-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl (DPAVBi),perylene and a derivative thereof (e.g., 2,5,8,11-tetra-t-butylperylene(TBP)), pyrene and a derivative thereof (e.g., 1,1-dipyrene,1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), etc.

The emission layer EML may include a suitable phosphorescent dopantmaterial. For example, a metal complex containing iridium (Ir), platinum(Pt), osmium (Os), gold (Au), titanium (Ti), zirconium (Zr), hafnium(Hf), europium (Eu), terbium (Tb), and/or thulium (Tm) may be utilizedas a phosphorescent dopant. For example, iridium(III)bis(4,6-difluorophenylpyridinato-N,C2′)picolinate (Flrpic),bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate (Firs),and/or platinum octaethyl porphyrin (PtOEP) may be utilized as aphosphorescent dopant. However, the embodiment of the present disclosureis not limited thereto.

The emission layer EML may include a quantum dot material. The core ofthe quantum dot may be selected from a Group II-VI compound, a GroupIII-VI compound, a Group compound, a Group III-V compound, a GroupIII-II-V compound, a Group IV-VI compound, a Group IV element, a GroupIV compound, or a combination thereof.

The Group II-VI compound may be selected from the group consisting of abinary compound selected from the group consisting of CdSe, CdTe, CdS,ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and a mixture thereof,a ternary compound selected from the group consisting of CdSeS, CdSeTe,CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe,CdZnTe, CdHgS,

CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and a mixturethereof, and a quaternary compound selected from the group consisting ofHgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe,HgZnSeS, HgZnSeTe, HgZnSTe, and a mixture thereof.

The Group III-VI compound may include a binary compound such as In₂S₃and/or In₂Se₃, a ternary compound such as InGaS₃ and/or InGaSe₃, or anycombination thereof.

The Group compound may be selected from a ternary compound selected fromthe group consisting of AgInS, AgInS₂, CuInS, CuInS₂, AgGaS₂, CuGaS₂CuGaO₂, AgGaO₂, AgAlO₂, and a mixture thereof, and a quaternary compoundsuch as AgInGaS₂ and/or CuInGaS₂.

The Group III-V compound may be selected from the group consisting of abinary compound selected from the group consisting of GaN, GaP, GaAs,GaSb, AIN, AIP, AlAs, AlSb, InN, InP, InAs, InSb, and a mixture thereof,a ternary compound selected from the group consisting of GaNP, GaNAs,GaNSb, GaPAs, GaPSb, AINP, AINAs, AINSb, AIPAs, AIPSb, InGaP, InAIP,InNP, InNAs, InNSb, InPAs, InPSb, and a mixture thereof, and aquaternary compound selected from the group consisting of GaAINP,GaAINAs, GaAINSb, GaAIPAs, GaAIPSb, GaInNP, GaInNAs, GaInNSb,

GaInPAs, GaInPSb, InAINP, InAINAs, InAINSb, InAIPAs, InAIPSb, and amixture thereof. In some embodiments, the Group III-V compound mayfurther include a Group II metal. For example, InZnP, etc. may beselected as a Group III-II-V compound.

The Group IV-VI compound may be selected from the group consisting of abinary compound selected from the group consisting of SnS, SnSe, SnTe,PbS, PbSe, PbTe, and a mixture thereof, a ternary compound selected fromthe group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe,SnPbS, SnPbSe, SnPbTe, and a mixture thereof, and a quaternary compoundselected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and amixture thereof. The Group IV element may be selected from the groupconsisting of Si, Ge, and a mixture thereof. The Group IV compound maybe a binary compound selected from the group consisting of SiC, SiGe,and a mixture thereof.

In this case, the binary compound, the ternary compound, and/or thequaternary compound may be present in a particle with a substantiallyuniform concentration distribution, or may be present in the sameparticle with a partially different concentration distribution. In someembodiments, the quantum dot may have a core/shell structure in whichone quantum dot is around (e.g., surrounds) another quantum dot. Thecore/shell structure may have a concentration gradient in which theconcentration of elements present in the shell decreases toward thecenter of the core.

In some embodiments, the quantum dot may have the above-describedcore/shell structure including a core containing nanocrystals and ashell around (e.g., surrounding) the core. The shell of the quantum dotmay serve as a protection layer to prevent or reduce the chemicaldeformation of the core so as to maintain semiconductor properties,and/or as a charging layer to impart electrophoresis properties to thequantum dot. The shell may be a single layer or a multilayer. An exampleof the shell of the quantum dot may include a metal or non-metal oxide,a semiconductor compound, or a combination thereof.

For example, the metal or non-metal oxide may be a binary compound suchas SiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO, FeO, Fe₂O₃, Fe₃O₄,CoO, Co₃O₄, and/or NiO, or a ternary compound such as MgAl₂O₄, CoFe₂O₄,NiFe₂O₄, and/or CoMn₂O₄, but the embodiment of the present disclosure isnot limited thereto.

In some embodiments, the semiconductor compound may be, for example,CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS,HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AIP, AlSb, etc., but theembodiment of the present disclosure is not limited thereto.

The quantum dot may have a full width at half maximum (FWHM) of a lightemission wavelength spectrum of about 45 nm or less, about 40 nm orless, or about 30 nm or less, and color purity or color reproducibilitymay be improved in the above ranges. In some embodiments, light emittedthrough such a quantum dot is emitted in all directions, and thus a wideviewing angle may be improved.

In some embodiments, although the form of a quantum dot is notparticularly limited as long as it is a form commonly utilized in theart, for example, a quantum dot in the form of spherical, pyramidal,multi-arm, and/or cubic nanoparticles, nanotubes, nanowires, nanofibers,nanoplate particles, etc. may be utilized.

The quantum dot may control the color of emitted light according to theparticle size thereof, and accordingly, the quantum dot may have one ormore suitable emission colors such as blue, red, and/or green.

In each light emitting element ED of embodiments illustrated in FIGS. 3to 6 , the electron transport region ETR is provided on the emissionlayer EML. The electron transport region ETR may include at least one ofthe hole blocking layer HBL, the electron transport layer ETL, or theelectron injection layer EIL, but the embodiment of the presentdisclosure is not limited thereto.

In the present disclosure, the electron transport region ETR may have asingle layer formed of a single material, a single layer formed of aplurality of different materials, or a multilayer structure including aplurality of layers formed of a plurality of different materials.

For example, the electron transport region ETR may have a single layerstructure of the electron injection layer EIL or the electron transportlayer ETL, and may have a single layer structure formed of an electroninjection material and an electron transport material. In someembodiments, the electron transport region ETR may have a single layerstructure formed of a plurality of different materials, or may have astructure in which an electron transport layer ETL/electron injectionlayer EIL, a hole blocking layer HBL/electron transport layerETL/electron injection layer EIL are stacked in the respective statedorder from the emission layer EML, but the embodiment of the presentdisclosure is not limited thereto. The electron transport region ETR mayhave a thickness, for example, from about 1,000 Å to about 1,500 Å.

In each light emitting element ED of embodiments illustrated in FIGS. 3to 6 , the electron transport region ETR is provided on the emissionlayer EML. The electron transport region ETR may include at least one ofthe hole blocking layer HBL, the electron transport layer ETL, or theelectron injection layer EIL, but the embodiment of the presentdisclosure is not limited thereto.

The electron transport region ETR may be formed by utilizing one or moresuitable methods such as a vacuum deposition method, a spin coatingmethod, a cast method, a Langmuir-Blodgett (LB) method, an inkjetprinting method, a laser printing method, and/or a laser induced thermalimaging (LITI) method.

The electron transport region ETR may include a compound represented byFormula ET-1:

In Formula ET-1, at least one selected from among X₁ to X₃ may be N, andthe remainder (e.g., the rest) may be CR_(a). R_(a) may be a hydrogenatom, a deuterium atom, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 30 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.Ari to Ara may each independently be a hydrogen atom, a deuterium atom,a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,a substituted or unsubstituted aryl group having 6 to 30 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 30 ring-forming carbon atoms.

In Formula ET-1, a to c may each independently be an integer of 0 to 10.In Formula ET-1, L₁ to L₃ may each independently be a direct linkage, asubstituted or unsubstituted arylene group having 6 to 30 ring-formingcarbon atoms, or a substituted or unsubstituted heteroarylene grouphaving 2 to 30 ring-forming carbon atoms. In some embodiments, when a toc are each an integer of 2 or more, L₁ to L₃ may each independently be asubstituted or unsubstituted arylene group having 6 to 30 ring-formingcarbon atoms, or a substituted or unsubstituted heteroarylene grouphaving 2 to 30 ring-forming carbon atoms.

The electron transport region ETR may include an anthracene-basedcompound. However, the embodiment of the present disclosure is notlimited thereto, and the electron transport region ETR may include, forexample, tris(8-hydroxyquinolinato)aluminum (Alq3),1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene,2,4,6-tris(3′-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine,2-(4-(N-phenylbenzoimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene,1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi),2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-diphenyl-1,10-phenanthroline (Bphen),3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ),4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ),2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD),bis(2-methyl-8-quinolinolato-N1,08)-(1,1-biphenyl-4-olato)aluminum(BAlq), berylliumbis(benzoquinolin-10-olate (Bebq₂),9,10-di(naphthalene-2-yl)anthracene (ADN),1,3-Bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB), or a mixturethereof.

The electron transport region ETR may include at least one selected fromamong Compound ET1 to Compound ET36:

In some embodiments, the electron transport regions ETR may include ametal halide such as LiF, NaCl, CsF, RbCI, RbI, Cul, and/or KI, alanthanide metal such as Yb, and a co-deposited material of the metalhalide and the lanthanide metal. For example, the electron transportregion ETR may include KI:Yb, RbI:Yb, LiF:Yb, etc. as a co-depositedmaterial. In some embodiments, the electron transport region ETR may beformed utilizing a metal oxide such as Li₂O and/or BaO, and/or8-hydroxyl-lithium quinolate (Liq), etc., but the embodiment of thepresent disclosure is not limited thereto. The electron transport regionETR may also be formed of a mixture material of an electron transportmaterial and an insulating organometallic salt. The organometallic saltmay be a material having an energy band gap of about 4 eV or more. Forexample, the organometallic salt may include, for example, a metalacetate, a metal benzoate, a metal acetoacetate, a metalacetylacetonate, and/or a metal stearate.

The electron transport region ETR may further include at least one of2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1), or4,7-diphenyl-1,10-phenanthroline (Bphen) in addition to theabove-described materials, but the embodiment of the present disclosureis not limited thereto.

The electron transport region ETR may include the above-describedcompounds of the electron transport region in at least one of theelectron injection layer EIL, the electron transport layer ETL, or thehole blocking layer HBL.

When the electron transport region ETR includes the electron transportlayer ETL, the electron transport layer ETL may have a thickness ofabout 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å.When the thickness of the electron transport layer ETL satisfies theaforementioned ranges, satisfactory electron transport characteristicsmay be obtained without a substantial increase in driving voltage. Whenthe electron transport region ETR includes the electron injection layerEIL, the electron injection layer EIL may have a thickness of about 1 Åto about 100 Å, for example, about 3 Å to about 90 Å. When the thicknessof the electron injection layer EIL satisfies the above-describedranges, satisfactory electron injection characteristics may be obtainedwithout a substantial increase in driving voltage.

The second electrode EL2 is provided on the electron transport regionETR. The second electrode EL2 may be a common electrode. The secondelectrode EL2 may be a cathode or an anode, but the embodiment of thepresent disclosure is not limited thereto. For example, when the firstelectrode EU is an anode, the second electrode EL2 may be a cathode, andwhen the first electrode EL1 is a cathode, the second electrode EL2 maybe an anode. The second electrode EL2 may include at least one selectedfrom among Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo,Ti, W, In, Sn, and Zn, at least one compound of two or more selectedfrom among these, at least one mixture of two or more selected fromamong these, or at least one oxide thereof.

The second electrode EL2 may be a transmissive electrode, atransflective electrode, or a reflective electrode. When the secondelectrode EL2 is the transmissive electrode, the second electrode EL2may be formed of a transparent metal oxide, for example, indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zincoxide (ITZO), etc.

When the second electrode EL2 is the transflective electrode or thereflective electrode, the second electrode EL2 may include Ag, Mg, Cu,Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca, LiF/AI, Mo, Ti, Yb, W,or a compound or mixture thereof (e.g., AgYb, and/or MgAg). In someembodiments, the second electrode EL2 may have a multilayer structureincluding a reflective film or a transflective film formed of theabove-described materials, and a transparent conductive film formed ofITO, IZO, ZnO, ITZO, etc. For example, the second electrode EL2 mayinclude one or more of the above-described metal materials, combinationsof two or more metal materials of the above-described metal materials,oxides of the above-described metal materials, and/or the like.

In some embodiments, the second electrode EL2 may be connected with anauxiliary electrode. When the second electrode EL2 is connected with theauxiliary electrode, the resistance of the second electrode EL2 may bedecreased.

In some embodiments, a capping layer CPL may further be disposed on thesecond electrode EL2 of the light emitting element ED of an embodiment.The capping layer CPL may include a multilayer or a single layer.

In an embodiment, the capping layer CPL may be an organic layer or aninorganic layer. For example, when the capping layer CPL contains aninorganic material, the inorganic material may include an alkali metalcompound (for example, LiF), an alkaline earth metal compound (forexample, MgF₂), SiON, SiN_(x), SiOy, etc.

For example, when the capping layer CPL contains an organic material,the organic material may include α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc,

N4,N4,N4′,N4′-tetra(biphenyl-4-yl)biphenyl-4,4′-diamine (TPD15),4,4′,4″-tris(carbazol sol-9-yl)triphenylamine (TCTA), etc., or mayinclude an epoxy resin, and/or an acrylate such as a methacrylate.However, the embodiment of the present disclosure is not limitedthereto, and the capping layer CPL may include at least one selectedfrom among Compounds P1 to P5:

In some embodiments, the refractive index of the capping layer CPL maybe about 1.6 or more. For example, the refractive index of the cappinglayer CPL may be about 1.6 or more with respect to light in a wavelengthrange of about 550 nm to about 660 nm.

Each of FIGS. 7 to 10 is a cross-sectional view of a display deviceaccording to an embodiment of the present disclosure. Hereinafter, indescribing the display devices of embodiments with reference to FIGS. 7to 10 , the duplicated features which have been described in FIGS. 1 to6 are not described again, but their differences will be mainlydescribed.

Referring to FIG. 7 , the display device DD-a according to an embodimentmay include a display panel DP including a display element layer DP-ED,a light control layer CCL disposed on the display panel DP, and a colorfilter layer CFL.

In an embodiment illustrated in FIG. 7 , the display panel DP mayinclude a base layer BS, a circuit layer DP-CL provided on the baselayer BS, and the display element layer DP-ED, and the display elementlayer DP-ED may include a light emitting element ED.

The light emitting element ED may include a first electrode EL1, a holetransport region HTR disposed on the first electrode EL1, an emissionlayer EML disposed on the hole transport region HTR, an electrontransport region ETR disposed on the emission layer EML, and a secondelectrode EL2 disposed on the electron transport region ETR. In someembodiments, the same structures of the light emitting elements of FIGS.3 to 6 as described above may be equally applied to the structure of thelight emitting element ED illustrated in FIG. 7 .

Referring to FIG. 7 , the emission layer EML may be disposed in anopening OH defined in a pixel defining film PDL. For example, theemission layer EML which is divided by the pixel defining film PDL andprovided corresponding to each light emitting regions PXA-R, PXA-G, andPXA-B may be to emit light in substantially the same wavelength range.In the display device DD of an embodiment, the emission layer EML may beto emit blue light. In some embodiments, unlike the configurationillustrated, the emission layer EML may be provided as a common layer inthe entire light emitting regions PXA-R, PXA-G, and PXA-B.

The light control layer CCL may be disposed on the display panel DP. Thelight control layer CCL may include a light conversion body. The lightconversion body may be a quantum dot, a phosphor, and/or the like. Thelight conversion body may be to emit provided light by converting thewavelength of the provided light and then emit a different color light.For example, the light control layer CCL may a layer containing thequantum dot or a layer containing the phosphor.

The light control layer CCL may include a plurality of light controlparts CCP1, CCP2 and CCP3. The light control parts CCP1, CCP2, and CCP3may be spaced apart from one another.

Referring to FIG. 7 , divided patterns BMP may be disposed between thelight control parts CCP1, CCP2 and CCP3 which are spaced apart from oneanother, but the embodiment of the present disclosure is not limitedthereto. FIG. 7 illustrates that the divided patterns BMP do not overlapthe light control parts CCP1, CCP2 and CCP3, but in some embodiments, atleast a portion of the edges of the light control parts CCP1, CCP2 andCCP3 may overlap the divided patterns BMP.

The light control layer CCL may include a first light control part CCP1containing a first quantum dot QD1 which converts a first color lightprovided from the light emitting element ED into a second color light, asecond light control part CCP2 containing a second quantum dot QD2 whichconverts the first color light into a third color light, and a thirdlight control part CCP3 which transmits the first color light.

In an embodiment, the first light control part CCP1 may provide redlight, which is the second color light, and the second light controlpart CCP2 may provide green light, which is the third color light. Thethird light control part CCP3 may provide blue light by transmitting theblue light, which is the first color light provided from the lightemitting element ED. For example, the first quantum dot QD1 may be a redquantum dot, and the second quantum dot QD2 may be a green quantum dot.The same as described above may be applied with respect to the quantumdots QD1 and

In some embodiments, the light control layer CCL may further include ascatterer SP. The first light control part CCP1 may include the firstquantum dot QD1 and the scatterer SP, the second light control part CCP2may include the second quantum dot QD2 and the scatterer SP, and thethird light control part CCP3 may not include (e.g., may exclude) anyquantum dots but may include the scatterer SP.

The scatterer SP may be inorganic particles. For example, the scattererSP may include at least one of TiO₂, ZnO, Al₂O₃, SiO₂, or hollow spheresilica. The scatterer SP may include any one selected from among TiO₂,ZnO, Al₂O₃, SiO₂, and hollow sphere silica, or may be a mixture of twoor more materials selected from among TiO₂, ZnO, Al₂O₃, SiO₂, and hollowsphere silica.

The first light control part CCP1, the second light control part CCP2,and the third light control part CCP3 each may include a correspondingone of the base resins BR1, BR2, and BR3 in which the quantum dots QD1and QD2 and the scatterer SP are dispersed. In an embodiment, the firstlight control part CCP1 may include the first quantum dot QD1 and thescatterer SP dispersed in the first base resin BR1, the second lightcontrol part CCP2 may include the second quantum dot QD2 and thescatterer SP dispersed in the second base resin BR2, and the third lightcontrol part CCP3 may include the scatterer SP dispersed in the thirdbase resin BR3. The base resins BR1, BR2, and BR3 are media in which thequantum dots QD1 and QD2 and the scatterer SP are dispersed, and may beformed of one or more suitable resin compositions, which may begenerally referred to as a binder. For example, the base resins BR1,BR2, and BR3 may be one or more acrylic-based resins, urethane-basedresins, silicone-based resins, epoxy-based resins, etc. The base resinsBR1, BR2, and BR3 may be transparent resins. In an embodiment, the firstbase resin BR1, the second base resin BR2, and the third base resin BR3may be the same as or different from one another.

The light control layer CCL may include a barrier layer BFL1. Thebarrier layer BFL1 may serve to prevent or reduce the penetration ofmoisture and/or oxygen (hereinafter, referred to as ‘moisture/oxygen’).The barrier layer BFL1 may be disposed on the light control parts CCP1,CCP2, and CCP3 to block or reduce the exposure of the light controlparts CCP1, CCP2 and CCP3 to moisture/oxygen. In some embodiments, thebarrier layer BFL1 may cover the light control parts CCP1, CCP2, andCCP3. In some embodiments, the barrier layer BFL2 may be providedbetween the light control parts CCP1, CCP2, and CCP3 and the colorfilter layer CFL (e.g., along the thickness direction).

The barrier layers BFL1 and BFL2 may include at least one inorganiclayer. For example, the barrier layers BFL1 and BFL2 may include aninorganic material. For example, the barrier layers BFL1 and BFL2 mayinclude a silicon nitride, an aluminum nitride, a zirconium nitride, atitanium nitride, a hafnium nitride, a tantalum nitride, a siliconoxide, an aluminum oxide, a titanium oxide, a tin oxide, a cerium oxide,a silicon oxynitride, a metal thin film which secures a transmittance,etc. In some embodiments, the barrier layers BFL1 and BFL2 may furtherinclude an organic film. The barrier layers BFL1 and BFL2 may be formedof a single layer or a plurality of layers.

In the display device DD of an embodiment, the color filter layer CFLmay be disposed on the light control layer CCL. For example, the colorfilter layer CFL may be directly disposed on the light control layerCCL. In this case, the barrier layer BFL2 may not be provided.

The color filter layer CFL may include color filters CF1, CF2, and CF3.The color filter layer CFL may include a first filter CF1 configured totransmit the second color light, a second filter CF2 configured totransmit the third color light, and a third filter CF3 configured totransmit the first color light. For example, the first filter CF1 may bea red filter, the second filter CF2 may be a green filter, and the thirdfilter CF3 may be a blue filter. The filters CF1, CF2, and CF3 each mayinclude a polymeric photosensitive resin and a pigment and/or dye. Thefirst filter CF1 may include a red pigment and/or dye, the second filterCF2 may include a green pigment and/or dye, and the third filter CF3 mayinclude a blue pigment and/or dye. The embodiment of the presentdisclosure is not limited thereto, and the third filter CF3 may notinclude (e.g., may exclude) any pigment or dye. The third filter CF3 mayinclude a polymeric photosensitive resin and may not include (e.g., mayexclude) any pigment or dye. The third filter CF3 may be transparent.The third filter CF3 may be formed of a transparent photosensitiveresin.

Furthermore, in an embodiment, the first filter CF1 and the secondfilter CF2 may each be a yellow filter. The first filter CF1 and thesecond filter CF2 may not be separated but be provided as one filter.The first to third filters CF1, CF2, and CF3 may be disposedcorresponding to the red light emitting region PXA-R, the green lightemitting region PXA-G, and the blue light emitting region PXA-B,respectively.

In some embodiments, the color filter layer CFL may include a lightshielding part. The color filter layer CFL may include a light shieldingpart disposed to overlap at the boundaries of neighboring filters CF1,CF2, and CF3. The light shielding part may be a black matrix. The lightshielding part may include an organic light shielding material or aninorganic light shielding material containing a black pigment and/ordye. The light shielding part may separate boundaries between theadjacent filters CF1, CF2, and CF3. In some embodiments, the lightshielding part may be formed of a blue filter.

A base substrate BL may be disposed on the color filter layer CFL. Thebase substrate BL may be a member which provides a base surface in whichthe color filter layer CFL, the light control layer CCL, and/or the likeare disposed. The base substrate BL may be a glass substrate, a metalsubstrate, a plastic substrate, etc. However, an embodiment of thepresent disclosure is not limited thereto, and the base substrate BL maybe an inorganic layer, an organic layer, or a composite material layer.In some embodiments, unlike the configuration illustrated, in anembodiment, the base substrate BL may not be provided.

FIG. 8 is a cross-sectional view illustrating a portion of a displaydevice according to an embodiment of the present disclosure. FIG. 8illustrates a cross-sectional view of a part corresponding to thedisplay panel DP of FIG. 7 . In the display device DD-TD of anembodiment, the light emitting element ED-BT may include a plurality oflight emitting structures OL-B1, OL-B2, and OL-B3. The light emittingelement ED-BT may include a first electrode EL1 and a second electrodeEL2 facing each other, and the plurality of light emitting structuresOL-B1, OL-B2, and OL-B3 sequentially stacked in the thickness directionbetween the first electrode EL1 and the second electrode EL2. The lightemitting structures OL-B1, OL-B2, and OL-B3 each may include an emissionlayer EML (FIG. 7 ), and a hole transport region HTR and an electrontransport region ETR disposed with the emission layer EML (FIG. 7 )located therebetween.

For example, the light emitting element ED-BT included in the displaydevice DD-TD of an embodiment may be a light emitting element having atandem structure and including a plurality of emission layers.

In an embodiment illustrated in FIG. 8 , light (e.g., light beams)respectively emitted from the light emitting structures OL-B1, OL-B2,and OL-B3 may all be blue light. However, the embodiment of the presentdisclosure is not limited thereto, and the light (e.g., light beams)respectively emitted from the light emitting structures OL-B1, OL-B2,and OL-B3 may have wavelength ranges different from one another. Forexample, the light emitting element ED-BT including the plurality oflight emitting structures OL-B1, OL-B2, and OL-B3 which emit light(e.g., light beams) having wavelength ranges different from one anothermay be to emit white light.

Charge generation layers CGL1 and CGL2 may be respectively disposedbetween two of the neighboring light emitting structures OL-B1, OL-B2,and OL-B3. The charge generation layers CGL1 and CGL2 may include ap-type or kind charge generation layer and/or an n-type or kind chargegeneration layer.

Referring to FIG. 9 , the display device DD-b according to an embodimentmay include light emitting elements ED-1, ED-2, and ED-3, in each ofwhich two emission layers are stacked. Compared with the display deviceDD of an embodiment illustrated in FIG. 2 , the embodiment illustratedin FIG. 9 is different in that the first to third light emittingelements ED-1, ED-2, and ED-3 each include two emission layers stackedin the thickness direction. In each of the first to third light emittingelements ED-1, ED-2, and ED-3, the two emission layers may be to emitlight in substantially the same wavelength region.

The first light emitting element ED-1 may include a first red emissionlayer EML-R1 and a second red emission layer EML-R2. The second lightemitting element ED-2 may include a first green emission layer EML-G1and a second green emission layer EML-G2. In some embodiments, the thirdlight emitting element ED-3 may include a first blue emission layerEML-B1 and a second blue emission layer EML-B2. An emission auxiliarypart OG may be disposed between the first red emission layer EML-R1 andthe second red emission layer EML-R2, between the first green emissionlayer EML-G1 and the second green emission layer EML-G2, and between thefirst blue emission layer EML-B1 and the second blue emission layerEML-B2.

The emission auxiliary part OG may include a single layer or amultilayer. The emission auxiliary part OG may include a chargegeneration layer. For example, the emission auxiliary part OG mayinclude an electron transport region, a charge generation layer, and ahole transport region that are sequentially stacked in the stated order.The emission auxiliary part OG may be provided as a common layer in thewhole (e.g., all) of the first to third light emitting elements ED-1,ED-2, and ED-3. However, the embodiment of the present disclosure is notlimited thereto, and the emission auxiliary part OG may be provided bybeing patterned within the openings OH defined in the pixel definingfilm PDL.

The first red emission layer EML-R1, the first green emission layerEML-G1, and the first blue emission layer EML-B1 may be disposed betweenthe electron transport region ETR and the emission auxiliary part OG.The second red emission layer EML-R₂, the second green emission layerEML-G2, and the second blue emission layer EML-B2 may be disposedbetween the emission auxiliary part OG and the hole transport regionHTR.

For example, the first light emitting element ED-1 may include the firstelectrode EL1, the hole transport region HTR, the second red emissionlayer EML-R₂, the emission auxiliary part OG, the first red emissionlayer EML-R₁, the electron transport region ETR, and the secondelectrode EL2 that are sequentially stacked in the stated order. Thesecond light emitting element ED-2 may include the first electrode EL1,the hole transport region HTR, the second green emission layer EML-G2,the emission auxiliary part OG, the first green emission layer EML-G1,the electron transport region ETR, and the second electrode EL2 that aresequentially stacked in the stated order. The third light emittingelement ED-3 may include the first electrode EL1, the hole transportregion HTR, the second blue emission layer EML-B2, the emissionauxiliary part OG, the first blue emission layer EML-B1, the electrontransport region ETR, and the second electrode EL2 that are sequentiallystacked in the stated order.

In some embodiments, an optical auxiliary layer PL may be disposed onthe display element layer DP-ED. The optical auxiliary layer PL mayinclude a polarizing layer. The optical auxiliary layer PL may bedisposed on the display panel DP and control reflected light in thedisplay panel DP due to external light. Unlike the configurationillustrated, the optical auxiliary layer PL in the display deviceaccording to an embodiment may not be provided.

Unlike FIGS. 8 and 9 , FIG. 10 illustrates that a display device DD-cincludes four light emitting structures OL-B1, OL-B2, OL-B3, and OL-C1.A light emitting element ED-CT may include a first electrode EL1 and asecond electrode EL2 facing each other, and first to fourth lightemitting structures OL-B1, OL-B2, OL-B3, and OL-C1 that are sequentiallystacked in stated order in the thickness direction between the firstelectrode EL1 and the second electrode EL2. Charge generation layersCGL1, CGL2, and CGL3 may be respectively disposed between the first tofourth light emitting structures OL-B1, OL-B2, OL-B3, and OL-C1. Amongthe four light emitting structures, the first to third light emittingstructures OL-B1, OL-B2, and OL-B3 may be to emit blue light, and thefourth light emitting structure OL-C1 may be to emit green light.However, the embodiment of the present disclosure is not limitedthereto, and the first to fourth light emitting structures OL-B1, OL-B2,OL-B3, and OL-C1 may be to emit light (e.g., light beams) in differentwavelength regions.

The charge generation layers CGL1, CGL2, and CGL3 disposed betweenadjacent light emitting structures OL-B1, OL-B2, OL-B3, and OL-C1 mayeach include a p-type or kind charge generation layer and/or an n-typeor kind charge generation layer.

At least one selected from among the light emitting structures OL-B1,OL-B2, OL-B3, and OL-C1 included in the display device DD-c of anembodiment may include the above-described polycyclic compound of anembodiment.

The above-described polycyclic compound of an embodiment includes astructure in which a triphenylsilyl group is fused with a carbazoleskeleton, and when the polycyclic compound is utilized as a hostmaterial of the light emitting element, an exciplex with a compoundutilized as a dopant material is not generated, and thus the colorpurity may be improved, and a relatively high T1 level may be exhibited,thereby achieving high efficiency of the light emitting element. In someembodiments, the polycyclic compound of an embodiment may have anexcellent or suitable electron transport ability, thereby providing aneffect of reduced driving voltage.

Hereinafter, with reference to Examples and Comparative Examples, apolycyclic compound according to an embodiment of the present disclosureand a light emitting element of an embodiment of the present disclosurewill be described in more detail. In addition, Examples described beloware only illustrations to assist the understanding of the presentdisclosure, and the scope of the present disclosure is not limitedthereto.

EXAMPLES 1. Synthesis of Polycyclic Compound

A synthetic method of a polycyclic compound according to the currentembodiment will be described in more detail by illustrating thesynthetic method of Compounds 2, 3, 9, 22, 24, and 31. In the followingdescriptions, the synthetic methods of the polycyclic compounds areprovided as examples, but the synthetic method according to anembodiment of the present disclosure is not limited to these Examples.

(1) Synthesis of Compound 2

Polycyclic Compound 2 according to an example may be synthesized by, forexample, the steps (acts) shown in Reaction Scheme 1:

1) Synthesis of Intermediate 2-1

1,3-dibromo-9H-carbazole (1 eq) and 1-bromo-2-iodobenzene (1.5 eq) werereacted under the condition (e.g., in the presence) of Pd₂dba₃ (0.05 eq)to obtain Intermediate 2-1. Intermediate 2-1 was identified with LC/MS.C₁₈H₁₀Br₃N M+1: 477.90

2) Synthesis of Intermediate 2-2

Intermediate 2-1 (1 eq) and 9H-carbazole (0.8 eq) were reacted under thecondition (e.g., in the presence) of Pd(pph₃)₄ (0.04 eq) to obtainIntermediate 2-2. Intermediate 2-2 was identified with LC/MS.

C₃₀H₁₈Br₂N₂ M+1: 565.12

3) Synthesis of Compound 2

Intermediate 2-2 (3.0 g) was dissolved in THF and stirred at about −78°C. for about 30 minutes. n-BuLi (4.26 mL, 2 eq) was slowly addeddropwise thereto and stirred at about −78° C. for about 1 hour.[1,1′-biphenyl]-4-yldichloro(phenyl)silane (CAS:18557-48-7) (1.75 g, 1eq) was quickly added dropwise thereto and stirred at room temperaturefor about 12 hours. After the reaction was completed, the reactionsolution was extracted with ethyl acetate to collect an organic layer.The collected organic layer was dried over magnesium sulfate and thesolvent was evaporated to obtain residuals. The obtained residuals wereseparated and purified by silica gel column chromatography to obtainCompound 2 (2.15 g, yield: 61%). Compound 2 was identified with LC-MSand ¹H-NMR, and the results thereof are listed in Table 1.

C₄₈H₃₂N₂Si M+1: 665.30

(2) Synthesis of Compound 3

Polycyclic Compound 3 according to an example may be synthesized by, forexample, the steps (acts) shown in Reaction Scheme 2:

1) Synthesis of Intermediate 3-1

Intermediate 2-1 (1 eq) and 2-(triphenylsilyl)-9H-carbazole (0.8 eq)were reacted under the condition (e.g., in the presence) of Pd(pph₃)₄(0.04 eq) to obtain Intermediate 3-1. Intermediate 3-1 was identifiedwith LC/MS.

C₄₈H₃₂Br₂N₂Si M+1: 823.47

2) Synthesis of Compound 3

Intermediate 3-1 (3.92 g) was dissolved in THF and stirred at about −78°C. for about 30 minutes. n-BuLi (3.8 mL, 2 eq) was slowly added dropwisethereto and stirred at about −78° C. for about 1 hour.Dichlorodiphenylsilane (CAS: 80-10-4) (1.2 g, 1 eq) was quickly addeddropwise thereto and stirred at room temperature for about 12 hours.After the reaction was completed, the reaction solution was extractedwith ethyl acetate to collect an organic layer. The collected organiclayer was dried over magnesium sulfate and the solvent was evaporated toobtain residuals. The obtained residuals were separated and purified bysilica gel column chromatography to obtain Compound 3 (2.69 g, yield:67%). Compound 3 was identified with LC-MS and ¹H-NMR, and the resultsthereof are listed in Table 1.

C₆₀H₄₂N₂Si₂ M+1: 847.33

(3) Synthesis of Compound 9

Polycyclic Compound 9 according to an example may be synthesized by, forexample, the steps (acts) shown in Reaction Scheme 3:

1) Synthesis of Intermediate 9-1

Intermediate 2-1 (1 eq) and 3,6-di-tert-butyl-9H-carbazole (0.8 eq) werereacted under the condition (e.g., in the presence) of Pd(pph₃)₄ (0.04eq) to obtain Intermediate 9-1. Intermediate 9-1 was identified withLC/MS.

C₄₈H₃₂Br₂N₂Si M+1: 677.24

2) Synthesis of Compound 9

Intermediate 9-1 (3.51 g) was dissolved in THF and stirred at about −78°C. for about 30 minutes. n-BuLi (4.14 mL, 2 eq) was slowly addeddropwise thereto and stirred at about −78° C. for about 1 hour.[1,1′-biphenyl]-3-yldichloro(phenyl)silane (1.7 g) was quickly addeddropwise thereto and stirred at room temperature for about 12 hours.After the reaction was completed, the reaction solution was extractedwith ethyl acetate to collect an organic layer. The collected organiclayer was dried over magnesium sulfate and the solvent was evaporated toobtain residuals. The obtained residuals were separated and purified bysilica gel column chromatography to obtain Compound 9 (2.61 g, yield:65%). Compound 9 was identified with LC-MS and ¹H-NMR, and the resultsthereof are listed in Table 1.

C₅₆H₄₈N₂Si M+1: 778.26

(4) Synthesis of Compound 22

Polycyclic Compound 22 according to an example may be synthesized by,for example, the steps (acts) shown in Reaction Scheme 4:

1) Synthesis of Intermediate 22-1

Intermediate 2-1 (1 eq) and 3,6-diphenyl-9H-carbazole (0.8 eq) werereacted under the condition (e.g., in the presence) of Pd(pph₃)₄ (0.04eq) to obtain Intermediate 22-1. Intermediate 22-1 was identified withLC/MS.

C₄₂H₂₆Br₂N₂ M+1: 717.41

2) Synthesis of Compound 22

Intermediate 22-1 (2.87 g) was dissolved in THF and stirred at about−78° C. for about 30 minutes. n-BuLi (3.20 mL, 2 eq) was slowly addeddropwise thereto and stirred at about −78° C. for about 1 hour.[1,1′-biphenyl]-4-yldichloro(phenyl)silane (1.32 g, 1 eq) was quicklyadded dropwise thereto and stirred at room temperature for about 12hours. After the reaction was completed, the reaction solution wasextracted with ethyl acetate to collect an organic layer. The collectedorganic layer was dried over magnesium sulfate and the solvent wasevaporated to obtain residuals. The obtained residuals were separatedand purified by silica gel column chromatography to obtain Compound 22(1.69 g, yield: 52%). Compound 22 was identified with LC-MS and ¹H-NMR,and the results thereof are listed in Table 1.

C₆₀H₄₀N₂Si M+1: 817.38

(5) Synthesis of Compound 24

Polycyclic Compound 24 according to an example may be synthesized by,for example, the steps (acts) shown in Reaction Scheme 5:

1) Synthesis of Intermediate 24-1

Intermediate 2-1 (1 eq) and 9H-3,9′-bicarbazole (0.8 eq) were reactedunder the condition (e.g., in the presence) of Pd(pph₃)₄ (0.04 eq) toobtain Intermediate 24-1. Intermediate 24-1 was identified with LC/MS.

C₄₂H₂₅Br₂N₃ M+1: 730.25

2) Synthesis of Compound 24

Intermediate 24-1 (4.22 g) was dissolved in THF and stirred at about−78° C. for about 30 minutes. n-BuLi (4.61 mL, 2 eq) was slowly addeddropwise thereto and stirred at about −78° C. for about 1 hour.[1,1′-biphenyl]-4-yldichloro(phenyl)silane (1.90 g) was quickly addeddropwise thereto and stirred at room temperature for about 12 hours.After the reaction was completed, the reaction solution was extractedwith ethyl acetate to collect an organic layer. The collected organiclayer was dried over magnesium sulfate and the solvent was evaporated toobtain residuals. The obtained residuals were separated and purified bysilica gel column chromatography to obtain Compound 24 (2.65 g, yield:55%). Compound 24 was identified with LC-MS and ¹H-NMR, and the resultsthereof are listed in Table 1.

C₆₀H₃₉N₃Si M+1: 831.50

(6) Synthesis of Compound 31

Polycyclic Compound 31 according to an example may be synthesized by,for example, the steps (acts) shown in Reaction Scheme 6:

1) Synthesis of Intermediate 31-1

1,6-dibromo-9H-carbazole (1 eq) and 1-bromo-2-iodobenzene (1.5 eq) werereacted under the condition (e.g., in the presence) of Pd₂dba₃ (0.05 eq)to obtain Intermediate 31-1. Intermediate 31-1 was identified withLC/MS.

C₁₈H₁₀Br₃N M+1: 477.88

2) Synthesis of Intermediate 31-2

Intermediate 31-1 (1 eq) and 3-phenyl-9H-carbazole (0.8 eq) were reactedunder the condition (e.g., in the presence) of Pd(pph₃)₄ (0.04 eq) toobtain Intermediate 31-2. Intermediate 31-2 was identified with LC/MS.

C₃₆H₂₂Br₂N₂ M+1: 641.12

3) Synthesis of Compound 31

Intermediate 31-2 (3.1 g) was dissolved in THF and stirred at about −78°C. for about 30 minutes. n-BuLi (3.86 mL, 2 eq) was slowly addeddropwise thereto and stirred at about −78° C. for about 1 hour.Dichlorodiphenylsilane (CAS: 80-10-4) (1.22 g, 1 eq) was quickly addeddropwise thereto and stirred at room temperature for about 12 hours.After the reaction was completed, the reaction solution was extractedwith ethyl acetate to collect an organic layer. The collected organiclayer was dried over magnesium sulfate and the solvent was evaporated toobtain residuals. The obtained residuals were separated and purified bysilica gel column chromatography to obtain Compound 31 (2.18 g, yield:68%). Compound 31 was identified with LC-MS and ¹H-NMR, and the resultsthereof are listed in Table 1.

C₄₈H₃₂N₂Si M+1: 665.39

TABLE 1 MS/FAB Compound ¹H NMR (CDCl₃, 400 MHz) found calc. Compound 28.55(d, 2H), 8.19(d, 1H), 665.30 664.23 7.94-7.16(m, 29H) Compound 38.53(d, 2H), 8.19(d, 1H), 847.33 846.29 7.83-7.80(m, 3H), 7.68(d, 1H),7.58-7.16(m, 35H) Compound 9 8.95(s, 1H), 8.55(d, 1H), 778.26 777.107.94-7.16(m, 28H)1.43(s, 18H) Compound 22 8.55(d, 1H), 8.30(d, 1H),817.38 816.30 8.13(d, 1H), 7.94-7.16(m, 37H) Compound 24 8.55(d, 2H),8.19(d, 1H), 831.50 830.08 7.94-7.16(m, 36H) Compound 31 8.55(d, 1H),8.29(d, 1H), 665.39 664.88 8.08(d, 1H), 7.99-7.33(m, 28H), 7.16(t, 1H)

2. Manufacturing and Evaluation of Light Emitting Elements

Evaluation of the light emitting elements including compounds ofExamples and Comparative Examples in a hole transport layer wasperformed as follows. The method for manufacturing the light emittingelement for the evaluation of the element is described below.

(1) Manufacturing of Light Emitting Elements

A 1,200 Å-thick ITO substrate was utilized as a first electrode. The ITOsubstrate was cleansed by ultrasonic waves utilizing isopropyl alcoholand pure water for about five minutes, respectively, and then wasirradiated with ultraviolet rays for about 30 minutes and exposed toozone and cleansed and prepared. The cleansed ITO substrate wasinstalled on a vacuum deposition apparatus.

N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB) was deposited in vacuumon the cleansed and prepared ITO substrate to form a hole injectionlayer. The hole injection layer was formed to have a thickness of about300 Å. Next, mCP was deposited in vacuum on the hole injection layer toform a hole transport layer. The hole transport layer was formed to havea thickness of about 200 Å.

Next, an emission layer including a respective Example Compound orComparative Example Compound was formed on the hole transport layer. Forthe emission layer, an Example Compound or Comparative Example Compoundwas co-deposited with Ir(pmp)₃ as a dopant material in a weight ratio ofabout 92:8 (Example Compound or Comparative Example Compound: dopant) toform a 250 Å-thick emission layer.

Then, on the upper portion of the emission layer,3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ) wasdeposited to form a 200 Å-thick electron transport layer, on the upperportion of the electron transport layer, LiF, which is an alkali metalhalide, was then deposited to form 10 Å-thick electron injection layer,and Al was deposited on the electron injection layer in vacuum to form a100 Å-thick second electrode. An LiF/Al electrode was formed on thesecond electrode, thereby manufacturing a light emitting element.

Example Compounds and Comparative Example Compounds utilized tomanufacture the light emitting elements are as follows:

Example Compounds

Comparative Example Compounds

In addition, compounds of each functional layer utilized to manufacturelight emitting elements are as follows:

(2) Evaluation of Light Emitting Element Properties

To evaluate properties of the light emitting elements according toExamples and Comparative Examples, driving voltages, current densities,and maximum quantum efficiencies at a current density of 10 mA/cm² weremeasured. The driving voltage and current density of the light emittingelement were measured by utilizing Source Meter (manufactured byKeithley Instruments, Inc., 2400 Series). The maximum quantum efficiencywas measured by utilizing an external quantum efficiency measurementapparatus, C9920-2-12 manufactured by Hamamatsu Photonics, Co., Japan.With respect to the evaluation of maximum quantum efficiency,brightness/current density was measured by utilizing brightnessphotometer in which wavelength sensitivity is calibrated, and themaximum quantum efficiency is converted assuming angular brightnessdistribution (Lambertian distribution) in which ideal diffuse reflectingsurface is contemplated. The results of the evaluation of properties ofthe light emitting elements are listed in Table 2.

TABLE 2 Examples Maximum of manu- Driving Effi- quantum Lumi- facturedEmission voltage ciency efficiency T1 nous elements layer (V) (Cd/A) (%)(eV) color Example 1 Example 4.1 18.9 29.3 3.03 Blue Compound 2 Example2 Example 4.6 17.5 28.7 3.04 Blue Compound 3 Example 3 Example 4.3 18.829.1 3.03 Blue Compound 9 Example 4 Example 4.5 18.7 28.6 3.01 BlueCompound 22 Example 5 Example 4.1 18.5 28.2 3.04 Blue Compound 24Example 6 Example 4.4 18.0 28.0 3.02 Blue Compound 31 ComparativeComparative 5.7 12.8 22.4 2.99 Blue Example 1 Example Compound C1Comparative Comparative 5.5 10.8 20.2 2.73 Blue Example 2 ExampleCompound C2 Comparative Comparative 5.2 14.2 24.5 2.89 Blue Example 3Example Compound C3

Referring to the results shown in Table 2, it may be seen that Examplesof the light emitting elements utilizing the polycyclic compoundsaccording to the present disclosure as host materials of the emissionlayers exhibit excellent or suitable luminous efficiency and low drivingvoltage characteristics compared with Comparative Examples.

Meanwhile, it may be seen that Comparative Example Compounds have adecrease in both (e.g., simultaneously) luminous efficiency and drivingvoltage characteristics compared with Example Compounds. In particular,Comparative Example Compound C2 utilized in Comparative Example 2 is astructure in which a silyl group is fused with a carbazole skeleton.However, it may be seen that unlike the polycyclic compound of anembodiment, the phenyl group bonded to Si is fused with the benzene ringlinked to the nitrogen atom of the carbazole skeleton to include a partin which the conjugation is expanded, and thus a relatively low T1 levelis exhibited, the luminous efficiency is not only significantly reduced,but also the driving voltage characteristic is reduced compared withExamples.

The light emitting element of an embodiment may include the polycycliccompound of an embodiment, thereby exhibiting a low driving voltagecharacteristic and providing an effect of improving luminous efficiency.

The polycyclic compound of an embodiment may be utilized as aluminescent material capable of improving a driving voltagecharacteristic and luminous efficiency of the light emitting element.

The use of “may” when describing embodiments of the present disclosurerefers to “one or more embodiments of the present disclosure”.

As used herein, the terms “substantially”, “about”, and similar termsare used as terms of approximation and not as terms of degree, and areintended to account for the inherent deviations in measured orcalculated values that would be recognized by those of ordinary skill inthe art. “About” or “approximately,” as used herein, is inclusive of thestated value and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” may mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

Any numerical range recited herein is intended to include all sub-rangesof the same numerical precision subsumed within the recited range. Forexample, a range of “1.0 to 10.0” is intended to include all subrangesbetween (and including) the recited minimum value of 1.0 and the recitedmaximum value of 10.0, that is, having a minimum value equal to orgreater than 1.0 and a maximum value equal to or less than 10.0, suchas, for example, 2.4 to 7.6. Any maximum numerical limitation recitedherein is intended to include all lower numerical limitations subsumedtherein and any minimum numerical limitation recited in thisspecification is intended to include all higher numerical limitationssubsumed therein. Accordingly, Applicant reserves the right to amendthis specification, including the claims, to expressly recite anysub-range subsumed within the ranges expressly recited herein.

The display device, and/or any other relevant devices or componentsaccording to embodiments of the present invention described herein maybe implemented utilizing any suitable hardware, firmware (e.g. anapplication-specific integrated circuit), software, or a combination ofsoftware, firmware, and hardware. For example, the various components ofthe device may be formed on one integrated circuit (IC) chip or onseparate IC chips. Further, the various components of the device may beimplemented on a flexible printed circuit film, a tape carrier package(TCP), a printed circuit board (PCB), or formed on one substrate.Further, the various components of the device may be a process orthread, running on one or more processors, in one or more computingdevices, executing computer program instructions and interacting withother system components for performing the various functionalitiesdescribed herein. The computer program instructions are stored in amemory which may be implemented in a computing device using a standardmemory device, such as, for example, a random access memory (RAM). Thecomputer program instructions may also be stored in other non-transitorycomputer readable media such as, for example, a CD-ROM, flash drive, orthe like. Also, a person of skill in the art should recognize that thefunctionality of various computing devices may be combined or integratedinto a single computing device, or the functionality of a particularcomputing device may be distributed across one or more other computingdevices without departing from the scope of the embodiments of thepresent disclosure.

Although the present disclosure has been described with reference to apreferred embodiment of the present disclosure, it will be understoodthat the present disclosure should not be limited to these preferredembodiments but one or more suitable changes and modifications can bemade by those skilled in the art without departing from the spirit andscope of the present disclosure.

Accordingly, the technical scope of the present disclosure is notintended to be limited to the contents set forth in the detaileddescription of the specification, but is intended to be defined by theappended claims, and equivalents thereof.

What is claimed is:
 1. A light emitting element comprising: a firstelectrode; a second electrode on the first electrode; and at least onefunctional layer between the first electrode and the second electrode,wherein the at least one functional layer comprises a polycycliccompound represented by Formula 1:

wherein, in Formula 1, R₁ and R₂ are each independently a hydrogen atom,a deuterium atom, a cyano group, a substituted or unsubstituted silylgroup, a substituted or unsubstituted alkyl group having 1 to 20 carbonatoms, a substituted or unsubstituted cycloalkyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms, R₃ and R₄ are each independently ahydrogen atom, a deuterium atom, or a group represented by Formula 2 orFormula 3, a and b are each independently an integer of 0 to 5, c is aninteger of 0 to 3, and d is an integer of 0 to 4:

wherein, in Formula 2, g is 0 or 1, and when g is 1, X is a directlinkage, in Formula 2 and Formula 3, R₅ to R₇ are each independently ahydrogen atom, a deuterium atom, a cyano group, a substituted orunsubstituted silyl group, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylgroup having 3 to 20 ring-forming carbon atoms, a substituted orunsubstituted heterocycloalkyl group having 3 to 20 ring-forming carbonatoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms, and/or bonded to an adjacent group toform a ring, e and f are each independently an integer of 0 to 4, h isan integer of 0 to 5, and

represents a linking position.
 2. The light emitting element of claim 1,wherein the at least one functional layer comprises an emission layer, ahole transport region between the first electrode and the emissionlayer, and an electron transport region between the emission layer andthe second electrode, and the emission layer comprises the polycycliccompound.
 3. The light emitting element of claim 2, wherein the emissionlayer is to emit delayed fluorescence or phosphorescence.
 4. The lightemitting element of claim 2, wherein the emission layer comprises a hostand a dopant, and the host comprises the polycyclic compound.
 5. Thelight emitting element of claim 2, wherein the emission layer is to emitlight having a center wavelength of about 430 nm to about 480 nm.
 6. Thelight emitting element of claim 1, wherein R₁ and R₂ are eachindependently a hydrogen atom, a deuterium atom, or a substituted orunsubstituted phenyl group.
 7. The light emitting element of claim 1,wherein R₃ and/or R₄ is represented by Formula 2 or Formula
 3. 8. Thelight emitting element of claim 1, wherein Formula 2 is represented byFormula 2-1 or Formula 2-2:

wherein, in Formula 2-1 and Formula 2-2, R_(5i) and R_(6i) are eachindependently a hydrogen atom, a deuterium atom, a substituted orunsubstituted silyl group, a substituted or unsubstituted alkyl grouphaving 1 to 10 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 20 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 20 ring-forming carbon atoms,and e and f are each independently an integer of 0 to
 4. 9. The lightemitting element of claim 1, wherein the polycyclic compound representedby Formula 1 is represented by Formula 1-1 or Formula 1-2:

wherein, in Formula 1-1 and Formula 1-2, R_(1i) is a hydrogen atom, adeuterium atom, a substituted or unsubstituted alkyl group having 1 to10 carbon atoms, or a substituted or unsubstituted aryl group having 6to 20 ring-forming carbon atoms, and R₅ to R₇, a, e, f, and h are thesame as respectively defined in Formula 1 to Formula
 3. 10. The lightemitting element of claim 9, wherein the polycyclic compound representedby Formula 1-1 is represented by Formula 1-1-1 or Formula 1-1-2:

wherein, in Formula 1-1-1 and Formula 1-1-2, R_(1i), R₅, R₆, a, e, f,and h are the same as respectively defined in Formula 1-1 and Formula 2.11. The light emitting element of claim 9, wherein the polycycliccompound represented by Formula 1-2 is represented by Formula 1-2-1 orFormula 1-2-2:

wherein, in Formula 1-2-1 and Formula 1-2-2, R_(1i), R₇, a, and h arethe same as respectively defined in Formula 1-2 and Formula
 3. 12. Thelight emitting element of claim 1, wherein R₅ to R₇ are eachindependently a hydrogen atom, a deuterium atom, or a group representedby any one selected from among R-1 to R-5:


13. The light emitting element of claim 1, wherein the polycycliccompound is represented by any one selected from among polycycliccompounds of Compound Group 1:


14. A polycyclic compound represented by Formula 1:

wherein, in Formula 1, R₁ and R₂ are each independently a hydrogen atom,a deuterium atom, a cyano group, a substituted or unsubstituted silylgroup, a substituted or unsubstituted alkyl group having 1 to 20 carbonatoms, a substituted or unsubstituted cycloalkyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms, R₃ and R₄ are each independently ahydrogen atom, a deuterium atom, or a group represented by Formula 2 orFormula 3, a and b are each independently an integer of 0 to 5, c is aninteger of 0 to 3, and d is an integer of 0 to 4:

wherein, in Formula 2, g is 0 or 1, and when g is 1, X is a directlinkage, in Formula 2 and Formula 3, R₅ to R₇ are each independently ahydrogen atom, a deuterium atom, a cyano group, a substituted orunsubstituted silyl group, a substituted or unsubstituted alkyl grouphaving 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylgroup having 3 to 20 ring-forming carbon atoms, a substituted orunsubstituted heterocycloalkyl group having 3 to 20 ring-forming carbonatoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20ring-forming carbon atoms, a substituted or unsubstitutedheterocycloalkenyl group having 3 to 20 ring-forming carbon atoms, asubstituted or unsubstituted aryl group having 6 to 60 ring-formingcarbon atoms, or a substituted or unsubstituted heteroaryl group having2 to 60 ring-forming carbon atoms, and/or bonded to an adjacent group toform a ring, e and f are each independently an integer of 0 to 4, h isan integer of 0 to 5, and

represents a linking position.
 15. The polycyclic compound of claim 14,wherein one selected from among R₃ and R₄ is represented by Formula 2 orFormula 3, and the other is a hydrogen atom or a deuterium atom.
 16. Thepolycyclic compound of claim 14, wherein Formula 2 is represented byFormula 2-1 or Formula 2-2:

wherein, in Formula 2-1 and Formula 2-2, R_(5i) and R_(6i) are eachindependently a hydrogen atom, a deuterium atom, a substituted orunsubstituted silyl group, a substituted or unsubstituted alkyl grouphaving 1 to 10 carbon atoms, a substituted or unsubstituted aryl grouphaving 6 to 20 ring-forming carbon atoms, or a substituted orunsubstituted heteroaryl group having 2 to 20 ring-forming carbon atoms,and e and f are each independently an integer of 0 to
 4. 17. Thepolycyclic compound of claim 14, wherein the polycyclic compoundrepresented by Formula 1 is represented by Formula 1-1 or Formula 1-2:

wherein, in Formula 1-1 and Formula 1-2, R_(1i) is a hydrogen atom, adeuterium atom, a substituted or unsubstituted alkyl group having 1 to10 carbon atoms, or a substituted or unsubstituted aryl group having 6to 20 ring-forming carbon atoms, and R₅ to R₇, a, e, f, and h are thesame as respectively defined in Formula 1 to Formula
 3. 18. Thepolycyclic compound of claim 17, wherein the polycyclic compoundrepresented by Formula 1-1 is represented by Formula 1-1-1 or Formula1-1-2:

wherein, in Formula 1-1-1 and Formula 1-1-2, R_(1i), R₅, R₆, a, e, and fare the same as respectively defined in Formula 1-1 and Formula
 2. 19.The polycyclic compound of claim 17, wherein the polycyclic compoundrepresented by Formula 1-2 is represented by Formula 1-2-1 or Formula1-2-2:

wherein, in Formula 1-2-1 and Formula 1-2-2, R_(1i), R₇, a, and h arethe same as respectively defined in Formula 1-2 and Formula
 3. 20. Thepolycyclic compound of claim 14, wherein the polycyclic compoundrepresented by Formula 1 is represented by any one selected from amongcompounds of Compound Group 1: